code: def _fix_connected_components(
      X,
      graph,
      n_connected_components,
      component_labels,
      mode="distance",
      metric="euclidean",
      **kwargs,
  ):
      """Add connections to sparse graph to connect unconnected components.
  
      For each pair of unconnected components, compute all pairwise distances
      from one component to the other, and add a connection on the closest pair
      of samples. This is a hacky way to get a graph with a single connected
      component, which is necessary for example to compute a shortest path
      between all pairs of samples in the graph.
  
      Parameters
      ----------
      X : array of shape (n_samples, n_features) or (n_samples, n_samples)
          Features to compute the pairwise distances. If `metric =
          "precomputed"`, X is the matrix of pairwise distances.
  
      graph : sparse matrix of shape (n_samples, n_samples)
          Graph of connection between samples.
  
      n_connected_components : int
          Number of connected components, as computed by
          `scipy.sparse.csgraph.connected_components`.
  
      component_labels : array of shape (n_samples)
          Labels of connected components, as computed by
          `scipy.sparse.csgraph.connected_components`.
  
      mode : {'connectivity', 'distance'}, default='distance'
          Type of graph matrix: 'connectivity' corresponds to the connectivity
          matrix with ones and zeros, and 'distance' corresponds to the distances
          between neighbors according to the given metric.
  
      metric : str
          Metric used in `sklearn.metrics.pairwise.pairwise_distances`.
  
      kwargs : kwargs
          Keyword arguments passed to
          `sklearn.metrics.pairwise.pairwise_distances`.
  
      Returns
      -------
      graph : sparse matrix of shape (n_samples, n_samples)
          Graph of connection between samples, with a single connected component.
      """
      if metric == "precomputed" and sparse.issparse(X):
          raise RuntimeError(
              "_fix_connected_components with metric='precomputed' requires the "
              "full distance matrix in X, and does not work with a sparse "
              "neighbors graph."
          )
  
      for i in range(n_connected_components):
          idx_i = np.flatnonzero(component_labels == i)
          Xi = X[idx_i]
          for j in range(i):
              idx_j = np.flatnonzero(component_labels == j)
              Xj = X[idx_j]
  
              if metric == "precomputed":
                  D = X[np.ix_(idx_i, idx_j)]
              else:
                  D = pairwise_distances(
                      Xi, Xj, metric=metric, **kwargs
                  )
  
              ii, jj = np.unravel_index(D.argmin(axis=None), D.shape)
              if mode == "connectivity":
                  graph[idx_i[ii], idx_j[jj]] = 1
                  graph[idx_j[jj], idx_i[ii]] = 1
              elif mode == "distance":
                  graph[idx_i[ii], idx_j[jj]] = D[ii, jj]
                  graph[idx_j[jj], idx_i[ii]] = D[ii, jj]
              else:
                  raise ValueError(
                      "Unknown mode=%r, should be one of ['connectivity', 'distance']."
                      % mode
                  )
  
      return graph
  
imports: import numpy
  from scipy import sparse
  from ..metrics.pairwise import pairwise_distances
  from ._param_validation import Integral, Interval, validate_params
label_desc: Use image node_id 2 for calling a global function with example usage: _fix_connected_components(X, graph, n_connected_components, component_labels, mode, metric) and returns: graph