code: def _uniform_stc(stc1, stc2):
      """Uniform vertices of two stcs.
  
      This function returns the stcs with the same vertices by
      inserting zeros in data for missing vertices.
      """
      if len(stc1.vertices) != len(stc2.vertices):
          raise ValueError(
              "Data in stcs must have the same number of vertices "
              "components. Got %d != %d."
              % (len(stc1.vertices), len(stc2.vertices))
          )
      idx_start1 = 0
      idx_start2 = 0
      stc1 = stc1.copy()
      stc2 = stc2.copy()
      all_data1 = []
      all_data2 = []
      for i, (vert1, vert2) in enumerate(
          zip(stc1.vertices, stc2.vertices)
      ):
          vert = np.union1d(vert1, vert2)
          data1 = np.zeros([len(vert), stc1.data.shape[1]])
          data2 = np.zeros([len(vert), stc2.data.shape[1]])
          data1[np.searchsorted(vert, vert1)] = stc1.data[
              idx_start1 : idx_start1 + len(vert1)
          ]
          data2[np.searchsorted(vert, vert2)] = stc2.data[
              idx_start2 : idx_start2 + len(vert2)
          ]
          idx_start1 += len(vert1)
          idx_start2 += len(vert2)
          stc1.vertices[i] = vert
          stc2.vertices[i] = vert
          all_data1.append(data1)
          all_data2.append(data2)
  
      stc1._data = np.concatenate(all_data1, axis=0)
      stc2._data = np.concatenate(all_data2, axis=0)
      return stc1, stc2
  
imports: from functools import partial
  import numpy
  from scipy.spatial.distance import cdist
  from ...utils import _check_option, _validate_type, fill_doc
label_desc: Use image node_id 3 for calling a global function with example usage: _uniform_stc(stc1, stc2) and returns: stc1,  stc2