protected LightweightTypeReference getFirstArgumentType() {
		if (!isExtension())
			return null;
		LightweightTypeReference result = getImplicitFirstArgumentType();
		if (result != null)
			return result;
		return getSyntacticReceiverType();
	}
protected LightweightTypeReference getFirstArgumentType ( ) { if ( ! isExtension ( ) ) return null ; LightweightTypeReference result = getImplicitFirstArgumentType ( ) ; if ( result != null ) return result ; return getSyntacticReceiverType ( ) ; }
/* @Nullable