code: def __call__(self, value, clip=None):
      # I'm ignoring masked values and all kinds of edge cases to make a
      # simple example...
      # Note also that we must extrapolate beyond vmin/vmax
      x, y = [self.vmin, self.vcenter, self.vmax], [0, 0.5, 1.0]
      return np.ma.masked_array(
          np.interp(value, x, y, left=-np.inf, right=np.inf)
      )
  
file_path: matplotlib/galleries/users_explain/colors/colormapnorms.py
imports: import matplotlib.pyplot
  import numpy
  from matplotlib import cm
  import matplotlib.cbook
  import matplotlib.colors
label_desc: Use image node_id 2 for calling the MidpointNormalize obj's underlying member method code with example usage: obj.__call__(value, clip) and returns: np