class_docstr: Mixin for user-defined rolling-window Terms.
  
  Implements `_compute` in terms of a user-defined `compute` function, which
  is mapped over the input windows.
  
  Used by CustomFactor, CustomFilter, CustomClassifier, etc.
code: def short_repr(self):
      return type(self).__name__ + "(%d)" % self.window_length
  
imports: from textwrap import dedent
  from numpy import array, full, recarray, vstack
  from pandas import NaT
  from catalyst.errors import WindowLengthNotPositive, UnsupportedDataType, NoFurtherDataError
  from catalyst.utils.control_flow import nullctx
  from catalyst.utils.input_validation import expect_types
  from catalyst.utils.sharedoc import format_docstring, PIPELINE_ALIAS_NAME_DOC, PIPELINE_DOWNSAMPLING_FREQUENCY_DOC
  from catalyst.utils.pandas_utils import nearest_unequal_elements
  from .downsample_helpers import select_sampling_indices, expect_downsample_frequency
  from .sentinels import NotSpecified
  from .term import Term
label_desc: Use image node_id 6 for calling the CustomTermMixin obj's underlying member method code with example usage: obj.short_repr() and returns: unknown