code: def _alias_mtype_check(return_type):
      """Return appropriate return_type in case an alias was used."""
      if return_type is None:
          return_type = "nested_univ"
      if return_type in ["numpy2d", "numpy2D", "np2d", "np2D"]:
          return_type = "numpyflat"
      if return_type in ["numpy3d", "np3d", "np3D"]:
          return_type = "numpy3D"
      return return_type
  
imports: import os
  import textwrap
label_desc: Use image node_id 1 for calling a global function with example usage: _alias_mtype_check(return_type) and returns: return_type