code: def apply_rbf_kernel(
      X: np.ndarray, precision: Optional[float] = None
  ) -> np.ndarray:
      """
      Estimates the RBF (Gaussian) kernel for the given input data.
  
      :param X: Input data.
      :param precision: Specific precision matrix for the RBF kernel. If None is given, this is inferred from the data.
      :return: The outcome of applying a RBF (Gaussian) kernel on the data.
      """
      X = shape_into_2d(X)
  
      distance_matrix = euclidean_distances(X, squared=True)
  
      if precision is None:
          precision = _median_based_precision(distance_matrix)
  
      return np.exp(-precision * distance_matrix)
  
file_path: dowhy/dowhy/gcm/independence_test/kernel_operation.py
imports: from typing import Optional
  import numpy
  from sklearn.kernel_approximation import Nystroem
  from sklearn.metrics import euclidean_distances
  from dowhy.gcm.util.general import shape_into_2d
label_desc: Use image node_id 1 for calling a global function with example usage: apply_rbf_kernel(X, precision) and returns: np