'''isFlowSpec/9'''

 * 'SOURCE'|'SINK'|'PATH'|'END TO END'
 * 'NIL'|package_name
 * component_type_identifier
 * 'NIL'|component_implementation_identifier
 * (flow spec) identifier
 * 'NIL'|source_feature_identifier|begin_flow_identifier
 * 'NIL'|destination_feature_identifier|end_flow_identifier 
 * 'NIL'|'REFINED TO'
 * line number (integer)

notes:

 * package_name is mandatory for AADL v2 (warning message 001)
 * fourth parameter should always be NIL