BMessenger()
case 1:	IsValid() should return false.
		IsTargetLocal() should return false.
		Target() should return NULL and NULL for looper.
		Team() should return -1.

BMessenger(const BHandler *handler, const BLooper *looper, status_t *result)
case 1:	handler is NULL, looper is NULL, result is NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
case 2:	handler is NULL, looper is NULL, result is not NULL =>
		IsValid() and IsTargetLocal() should return false.
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		result is set to B_BAD_VALUE.
case 3:	handler is NULL, looper is not NULL, result is not NULL =>
		IsValid() and IsTargetLocal() should return true.
		Target() should return NULL and the correct value for looper.
		Team() should return this team.
		result is set to B_OK.
case 4:	handler is not NULL, looper is NULL, result is not NULL,
		handler doesn't belong to a looper =>
		IsValid() and IsTargetLocal() should return false.
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		result is set to B_MISMATCHED_VALUES.
case 5:	handler is not NULL, looper is NULL, result is not NULL
		handler does belong to a looper =>
		IsValid() and IsTargetLocal() should return true.
		Target() should return the correct handler and handler->Looper()
		for looper.
		Team() should return this team.
		result is set to B_OK.
case 6:	handler is not NULL, looper is not NULL, result is not NULL
		handler does belong to the looper =>
		IsValid() and IsTargetLocal() should return true.
		Target() should return the correct handler and the correct value
		for looper.
		Team() should return this team.
		result is set to B_OK.
case 7:	handler is not NULL, looper is not NULL, result is not NULL
		handler does belong to a different looper =>
		IsValid() and IsTargetLocal() should return false.
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		result is set to B_MISMATCHED_VALUES.

BMessenger(const BMessenger &from)
case 1:	from is uninitialized =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
case 2:	from is properly initialized to a local target =>
		IsValid() and IsTargetLocal() should return true
		Target() should return the same values as for from.
		Team() should return this team.

BMessenger(const char *signature, team_id team, status_t *result)
case 1:	signature is NULL, team is -1, result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		(result should be set to B_BAD_TYPE.)
case 2:	signature is not NULL, but identifies no running application,
		team is -1, result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		(result should be set to B_BAD_VALUE.)
case 3:	signature is NULL, team is > 0, but identifies no running application,
		result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		(result should be set to B_BAD_TEAM_ID.)
case 4:	signature is not NULL and identifies a running B_ARGV_ONLY application,
		team is -1, result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return the remote app's team ID.
		(result should be set to B_BAD_TYPE.)
case 5:	signature is NULL,
		team is > 0 and identifies a running B_ARGV_ONLY application,
		result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return the remote app's team ID.
		(result should be set to B_BAD_TYPE.)
case 6:	signature is not NULL and identifies a "normal" running application,
		team is -1, result is (not) NULL =>
		IsValid() should return true
		IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return the team ID of the remote application.
		(result should be set to B_OK.)
case 7:	signature is NULL,
		team is > 0 and identifies a "normal" running application,
		result is (not) NULL =>
		IsValid() should return true, false after the app terminated
		IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return the team ID of the remote application (team).
		(result should be set to B_OK.)
case 8:	signature is not NULL and team is > 0, but both identify different
		applications, result is (not) NULL =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
		(result should be set to B_MISMATCHED_VALUES.)
case 9:	signature is not NULL,
		team is > 0 and both identify the same application (more than one
		app with the given signature are running), result is (not) NULL =>
		IsValid() should return true
		IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return the team ID of the remote application (team).
		(result should be set to B_OK.)

bool IsTargetLocal() const
case 1:	this is uninitialized =>
		should return false.
case 2:	this is initialized to local target with preferred handler =>
		should return true.
case 3:	this is initialized to local target with specific handler =>
		should return true.
case 4:	this is initialized to local target with preferred handler =>
		should return false.
case 5:	this is initialized to remote target with specific handler =>
		should return false.

BHandler *Target(BLooper **looper) const
case 1:	this is uninitialized, looper is NULL =>
		should return NULL.
case 2:	this is initialized to local target with preferred handler,
		looper is NULL =>
		should return NULL.
case 3:	this is initialized to local target with specific handler,
		looper is NULL =>
		should return correct handler.
case 4:	this is initialized to remote target with preferred handler,
		looper is NULL =>
		should return NULL.
case 5:	this is initialized to remote target with specific handler,
		looper is NULL =>
		should return NULL.
other cases included in BMessenger(...) cases

bool LockTarget() const
case 1:	this is uninitialized =>
		should return false.
case 2:	this is initialized to local target with preferred handler,
		looper is not locked =>
		should lock the looper and return true.
case 3:	this is initialized to local target with specific handler,
		looper is not locked =>
		should lock the looper and return true.
case 4:	this is initialized to local target with preferred handler,
		looper is locked by another thread =>
		should block until the looper is unlocked, lock it and return true.
case 5:	this is initialized to local target with specific handler,
		looper is locked by another thread =>
		should block until the looper is unlocked, lock it and return true.
case 6:	this is initialized to remote target with preferred handler,
		looper is not locked =>
		should not lock the looper and return false.
case 7:	this is initialized to remote target with specific handler,
		looper is not locked =>
		should not lock the looper and return false.

status_t LockTargetWithTimeout(bigtime_t timeout) const
case 1:	this is uninitialized =>
		should return B_BAD_VALUE.
case 2:	this is initialized to local target with preferred handler,
		looper is not locked =>
		should lock the looper and return B_OK.
case 3:	this is initialized to local target with specific handler,
		looper is not locked =>
		should lock the looper and return B_OK.
case 4:	this is initialized to local target with preferred handler,
		looper is locked by another thread, timeout is 100ms =>
		should block until the looper is unlocked (after 50ms), lock it
		and return B_OK.
case 5:	this is initialized to local target with preferred handler,
		looper is locked by another thread, timeout is 25ms =>
		should block for 25ms, not until the looper is unlocked (after 50ms),
		should return B_TIMED_OUT.
case 6:	this is initialized to local target with specific handler,
		looper is locked by another thread, timeout is 100ms =>
		should block until the looper is unlocked (after 50ms), lock it
		and return B_OK.
case 7:	this is initialized to local target with specific handler,
		looper is locked by another thread, timeout is 25ms =>
		should block for 25ms, not until the looper is unlocked (after 50ms),
		should return B_TIMED_OUT.
case 8:	this is initialized to remote target with preferred handler,
		looper is not locked =>
		should not lock the looper and return B_BAD_VALUE.
case 9:	this is initialized to remote target with specific handler,
		looper is not locked =>
		should not lock the looper and return B_BAD_VALUE.

bool IsValid() const
included in BMessenger(...) cases

team_id Team() const
included in BMessenger(...) cases

BMessenger &operator=(const BMessenger &from)
case 1:	from is uninitialized =>
		IsValid() and IsTargetLocal() should return false
		Target() should return NULL and NULL for looper.
		Team() should return -1.
case 2:	from is properly initialized to a local target (preferred handler) =>
		IsValid() and IsTargetLocal() should return true
		Target() should return the same values as for from.
		Team() should return this team.
case 3:	from is properly initialized to a local target (specific handler) =>
		IsValid() and IsTargetLocal() should return true
		Target() should return the same values as for from.
		Team() should return this team.

bool operator==(const BMessenger &other) const
case 1:	this and other are uninitialized =>
		should return true.
case 2:	this is initialized, other is uninitialized, and vice versa =>
		should return false.
case 3:	this and other are initialized, different cases:
		- same object => true
		- different objects same target => true
		- looper preferred handler vs. same looper but the looper itself as
		  handler => false
		- looper preferred handler vs. other looper preferred handler => false
		- looper preferred handler vs. other looper specific handler => false
		- local looper vs. remote looper => false

bool operator!=(const BMessenger &a, const BMessenger &b)
included in == cases

bool operator<(const BMessenger &a, const BMessenger &b)
case 1:	set fields of a and b manually =>
		should return whatever the reference implementation returns.

status_t SendMessage(uint32 command, BHandler *replyTo) const
case 1:	this is uninitialized, replyTo is NULL =>
		should return B_BAD_PORT_ID.
case 2:	this is uninitialized, replyTo points to a valid handler  =>
		should return B_BAD_PORT_ID.
case 3:	this is initialized to a local/remote target with preferred/specific
		handler, replyTo is NULL =>
		should deliver the message and return B_OK.
case 4:	this is initialized to a local/remote target with preferred/specific
		handler, replyTo points to a valid handler =>
		should deliver the message and return B_OK, a reply should be posted
		to the reply handler.

status_t SendMessage(BMessage *message, BHandler *replyTo,
					 bigtime_t timeout) const
case 1:	message is NULL, replyTo is NULL, timeout is B_INFINITE_TIMEOUT =>
		should return B_BAD_VALUE.
other cases similar to those of SendMessage(uint32, BHandler *). Each one with
a timeout of B_INFINITE_TIMEOUT, 0 and some ms. For the last two
timeouts in failure cases B_WOULD_BLOCK/B_TIMED_OUT should be returned.

status_t SendMessage(BMessage *message, BMessenger replyTo,
					 bigtime_t timeout) const
cases similar to those of SendMessage(BMessage *, BHandler *, bigtime_t).
An invalid replyTo messenger causes the same behavior as a NULL handler.

status_t SendMessage(uint32 command, BMessage *reply) const
case 1:	this is uninitialized, reply is NULL =>
		should return B_BAD_PORT_ID or B_BAD_VALUE.
case 2:	this is uninitialized, replyTo points to a valid message  =>
		should return B_BAD_PORT_ID.
case 3:	this is initialized to a local/remote target with preferred/specific
		handler, reply is NULL =>
		should return B_BAD_VALUE.
case 4:	this is initialized to a local/remote target with preferred/specific
		handler, reply points to a valid message =>
		should deliver the message, wait for a reply and return B_OK,
		reply should contain the reply.

status_t SendMessage(BMessage *message, BMessage *reply,
					 bigtime_t deliveryTimeout,
					 bigtime_t replyTimeout) const
cases similar to those of SendMessage(uint32, BMessage *). deliveryTimeout and
replyTimeout are B_INFINITE_TIMEOUT, 0 or some ms. In timeout cases
B_WOULD_BLOCK/B_TIMED_OUT should be returned.