code: def _same_elements_per_channel(x):
      """
      Test if a 3D (H,W,C) matrix x has the same element in each (H,W) matrix for each channel
      """
      eps = 1e-5
      dims = x.shape
      for c in range(dims[-1]):
          xc = x[:, :, c].flatten()
          if not np.all(np.absolute(xc - xc[0]) < eps):
              return False
      return True
  
imports: from .None import _utils
  import keras
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: _same_elements_per_channel(x) and returns: True, False