Tells if all the required values in op have been defined.
if xml_file is not null, the validity of op is tested against that specification, and not against the current op's specification.
an XML specification file (see gda.server_operation.ServerOperation.new_) or null
true if op is valid
ServerOperationException
Tells if all the required values in op have been defined.
if xml_file is not null, the validity of op is tested against that specification, and not against the current op's specification.