code: def cost1(x):
      """Cost function."""
      qml.Rot(*x, wires=0)
      return qml.expval(qml.PauliZ(0))
  
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: cost1(x) and returns: qml