code: def mandel(size, x_center, y_center, max_iteration):
      out = [[0 for i in range(size)] for j in range(size)]
      for i in range(size):
          "omp parallel for"
          for j in range(size):
              x, y = (
                  x_center + 4.0 * float(i - size / 2) / size,
                  y_center + 4.0 * float(j - size / 2) / size,
              )
  
              a, b = (0.0, 0.0)
              iteration = 0
  
              while (
                  a**2 + b**2 <= 4.0 and iteration < max_iteration
              ):
                  a, b = a**2 - b**2 + x, 2 * a * b + y
                  iteration += 1
              if iteration == max_iteration:
                  color_value = 255
              else:
                  color_value = iteration * 10 % 255
              out[i][j] = color_value
      return out
  
label_desc: Use image node_id 1 for calling a global function with example usage: mandel(size, x_center, y_center, max_iteration) and returns: out