class_docstr: Portal input for monkey-patching of mask in predict mode.
code: def __init__(self):
      super().__init__(name="_PortalInput", n_out=1, n_in=1)
      self._portal_output = _PortalOutput(self)
  
imports: import functools
  from trax import layers
  from trax.fastmath import numpy
  from trax.models.reformer import reformer
  from trax.models.research import configurable_transformer
  from trax.models.research import transformer2
label_desc: Use image node_id 1 to create a new _PortalInput object from inherited base classes: tl with example: obj = _PortalInput()