code: def mask(image):
      data = image.pixel_data
  
      mask = numpy.ones_like(data, dtype=bool)
  
      mask[data < 50] = False
  
      mask[data > 205] = False
  
      return mask
  
imports: import base64
  import io
  import zlib
  import numpy
  import pytest
  import skimage.data
  import skimage.exposure
  import cellprofiler_core.image
  import cellprofiler_core.measurement
  import cellprofiler_core.module
  import cellprofiler_core.modules.injectimage
  import cellprofiler.modules.rescaleintensity
  import cellprofiler_core.object
  import cellprofiler_core.pipeline
  import cellprofiler_core.preferences
  import cellprofiler_core.workspace
label_desc: Use image node_id 2 for calling a global function with example usage: mask(image) and returns: mask