class_docstr: I am a demo
class_docstr_tok: ["I","am","a","demo"]
code: def __call__(
      self,
      demoposarg,
      demooptposarg1=99,
      demooptposarg2=999,
      demoarg=100,
  ):
      return demoarg
  
file_path: datalad/datalad/tests/test_interface.py
imports: import re
  from datalad.interface.base import Interface, get_api_name
  from datalad.support import constraints
  from datalad.support.param import Parameter
  from datalad.tests.utils_pytest import assert_equal, assert_in, assert_is, assert_raises, assert_re_in, assert_true, swallow_outputs
label_desc: Use image node_id 1 for calling the Demo obj's underlying member method code with example usage: obj.__call__(demoposarg, demooptposarg1, demooptposarg2, demoarg) and returns: demoarg