@staticmethod<EOL><INDENT>def _is_sub_intrinsic(data):<DEDENT>
return isinstance(data, dict) and len(data) == <NUM_LIT:1> and LambdaUri._FN_SUB in data<EOL>
Is this input data a Fn::Sub intrinsic function

Parameters
----------
data
    Data to check

Returns
-------
bool
    True if the data Fn::Sub intrinsic function