code: def dummy(x: Field, *, params=None):
      """Dummy operator for testing purposes."""
      return x
  
file_path: jaxdf/jaxdf/operators/dummy.py
imports: from jaxdf.core import operator
  from jaxdf.discretization import Continuous, Field, OnGrid
label_desc: Use image node_id 2 for calling a global function with example usage: dummy(x) and returns: x