JavaModelExceptionobjects to indicate what went wrong.
Java model status object are distinguished by their plug-in id:
getCode returns one of the status codes declared in
A Java model status may also carry additional information (that is, in
addition to the information defined in
nullif the failure is not one of
getCode() == IJavaModelStatusConstants.ELEMENT_DOES_NOT_EXIST.
trueif the status code indicates that a Java model element does not exist