code: def pow3(x, c, a, alpha):
      """pow3
  
      Parameters
      ----------
      x : int
      c : float
      a : float
      alpha : float
  
      Returns
      -------
      float
          c - a * x**(-alpha)
      """
      return c - a * x ** (-alpha)
  
file_path: nni/nni/algorithms/hpo/curvefitting_assessor/curvefunctions.py
imports: import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: pow3(x, c, a, alpha) and returns: unknown