code: def squeezed_cov(r, phi, hbar=2):
      r"""Returns the squeezed covariance matrix of a squeezed state.
  
      Args:
          r (float): the squeezing magnitude
          p (float): the squeezing phase :math:`\phi`
          hbar (float): (default 2) the value of :math:`\hbar` in the commutation
              relation :math:`[\x,\p]=i\hbar`
      Returns:
          array: the squeezed state
      """
      cov = (
          np.array([[math.exp(-2 * r), 0], [0, math.exp(2 * r)]])
          * hbar
          / 2
      )
  
      R = rotation(phi / 2)
  
      return R @ cov @ R.T
  
imports: import math
  import cmath
  import numpy
  from scipy.special import factorial
  import pennylane
  from pennylane.ops import Identity
  from pennylane import Device
  from .._version import __version__
label_desc: Use image node_id 12 for calling a global function with example usage: squeezed_cov(r, phi, hbar) and returns: unknown