code: public FunctionTypeReference getAsFunctionTypeReference(ParameterizedTypeReference typeReference) {
  		FunctionTypeKind functionTypeKind = getFunctionTypeKind(typeReference);
  		if (functionTypeKind == FunctionTypeKind.PROCEDURE) {
  			return getAsProcedureOrNull(typeReference);
  		} else if (functionTypeKind == FunctionTypeKind.FUNCTION) {
  			return getAsFunctionOrNull(typeReference);
  		}
  		return null;
  	}
docs: /* @Nullable