code: def colormesh(X, Y):
      
      X1 = X[0:-1, 0:-1].ravel()
      Y1 = Y[0:-1, 0:-1].ravel()
      X2 = X[1:, 0:-1].ravel()
      Y2 = Y[1:, 0:-1].ravel()
      X3 = X[1:, 1:].ravel()
      Y3 = Y[1:, 1:].ravel()
      X4 = X[0:-1, 1:].ravel()
      Y4 = Y[0:-1, 1:].ravel()
  
      X = np.column_stack([X1, X2, X3, X4, X1])
      Y = np.column_stack([Y1, Y2, Y3, Y4, Y1])
      return X, Y
docs: Generates line paths for a quadmesh given 2D arrays of X and Y
      coordinates.