class_docstr: a basic test invocation item. Note that for a single function
  there might be multiple test invocation items.
code: def location(self):
      try:
          return self._location
      except AttributeError:
          location = self.reportinfo()
          fspath = self.session._node_location_to_relpath(location[0])
          location = (fspath, location[1], str(location[2]))
          self._location = location
          return location
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import warnings
  import py
  import six
  import _pytest._code
  from _pytest.compat import getfslineno
  from _pytest.mark.structures import NodeKeywords
  from _pytest.outcomes import fail
label_desc: Use image node_id 4 for calling the Item obj's underlying member method code with example usage: obj.location() and returns: self, location