function computeFullTarget(sODataMessageTarget) {
				return Array.isArray(vFullTargetPrefix)
					? vFullTargetPrefix.shift() + sODataMessageTarget
					: (vFullTargetPrefix || sTargetPrefix) + sODataMessageTarget;
			}
Adds a message to the array of expected messages for this test based on the given OData
message object, the target prefix and the full target prefix. If the given oODataMessage
is <code>null</code>, no message is added. That allows using the "?" operator in
<code>expectMessage</code> calls for messages that depend on the test fixture. No extra
<code>if</code> statement is needed.

@param {object} oODataMessage
  An OData message object as returned by <code>createResponseMessage</code> or
  <code>null</code>
@param {string|string[]|object} vTargetPrefix
  The prefix for the target; if vTargetPrefix is not of type string or an array of
  strings the given object may have following properties: <code>path</code> and
  <code>isComplete</code>;  note that a given array is modified
@param {boolean} vTargetPrefix.isComplete
  Whether <code>vTargetPrefix.path</code> is the complete message target or
  <code>vTargetPrefix.path</code> is a prefix for the <code>oODataMessage.target</code>
@param {string} vTargetPrefix.path
  A path or a path prefix for the target
@param {string|string[]} [vFullTargetPrefix=vTargetPrefix]
  The prefix for the full target; if not given <code>vTargetPrefix</code> is also used as
  prefix for the <code>fullTarget</code>; if vTargetPrefix is an array of strings the
  vFullTargetPrefix must be given as an array with the equivalent number of strings; note
  that a given array is modified
@param {boolean} [bResetMessages]
  Whether existing expected messages are reset before the new message is added
@returns {object}
  The test instance for chaining