code: def _solve_triangular_common(A, b, lower):
      """Solves Ax=b when A is a triangular matrix."""
      if A.size == 0 and b.shape[0] == 0:
          return np.zeros((b.shape))
      else:
          return solve_triangular(A, b, lower=lower)
  
imports: from __future__ import print_function
  from __future__ import division
  import numpy
  from scipy.sparse import dok_matrix
  from scipy.linalg import solve_triangular
label_desc: Use image node_id 14 for calling a global function with example usage: _solve_triangular_common(A, b, lower) and returns: np, solve_triangular