code: def _IsSingletonList(testcases):
      """True iff testcases contains only a single non-tuple element."""
      return len(testcases) == 1 and not isinstance(testcases[0], tuple)
  
imports: import collections
  import functools
  import re
  import types
  import uuid
  import six
label_desc: Use image node_id 5 for calling a global function with example usage: _IsSingletonList(testcases) and returns: unknown