code: def nin(self):
      sig = inspect.signature(self.func)
      return len(
          [
              param
              for param in sig.parameters.values()
              if param.kind == param.POSITIONAL_ONLY
          ]
      )
  
file_path: ivy/ivy/functional/frontends/numpy/ufunc/methods.py
imports: import inspect
  from math import inf
  import ivy.functional.frontends.numpy
label_desc: Use image node_id 3 for calling the ufunc obj's underlying member method code with example usage: obj.nin() and returns: len