code: def richardson_extrapolate(x, y):
      r"""Polynomial fit where the degree of the polynomial is fixed to being equal to the length of ``x``.
  
      In a nutshell, this function is calling  :func:`~.pennylane.transforms.poly_extrapolate` with ``order = len(x)-1``.
      This function is compatible with all interfaces supported by pennylane.
  
      Args:
          x (Array): Data in x
          y (Array): Data in y = f(x)
  
      Returns:
          float: Extrapolated value at f(0).
  
      .. seealso:: :func:`~.pennylane.transforms.poly_extrapolate`, :func:`~.pennylane.transforms.mitigate_with_zne`
  
      **Example:**
  
      >>> x = np.linspace(1, 10, 5)
      >>> y = x**2 + x + 1 + 0.3 * np.random.rand(len(x))
      >>> qml.transforms.richardson_extrapolate(x, y)
      tensor(1.15105156, requires_grad=True)
  
      """
      return poly_extrapolate(x, y, len(x) - 1)
  
file_path: pennylane/pennylane/transforms/mitigate.py
imports: from copy import copy
  from typing import Any, Dict, Optional, Sequence, Callable
  from pennylane import apply, adjoint
  from pennylane.math import mean, shape, round
  from pennylane.queuing import AnnotatedQueue
  from pennylane.tape import QuantumTape, QuantumScript
  from pennylane.transforms import transform
  import pennylane
label_desc: Use image node_id 6 for calling a global function with example usage: richardson_extrapolate(x, y) and returns: poly_extrapolate