code: def Rphi(phi):
      r"""One-qubit phase shift.
  
      Args:
          phi (float): phase shift angle
      Returns:
          array: unitary 2x2 phase shift matrix
      """
      return math.array([[1, 0], [0, math.exp(1j * phi)]], like=phi)
  
imports: import pennylane
  from pennylane import numpy
  from pennylane import math
label_desc: Use image node_id 1 for calling a global function with example usage: Rphi(phi) and returns: math