code: def f(x):
      x0, x1 = x
      return (
          x0 ** np.sin(x0)
          + x1**4
          + 6 * x1**3
          - 5 * x1**2
          - 40 * x1
          + 35
      )
  
file_path: mystic/examples2/output_constrain.py
imports: import numpy
  import mystic
  from matplotlib import cm
  import matplotlib.pyplot
label_desc: Use image node_id 1 for calling a global function with example usage: f(x) and returns: unknown