code: def find_grid_embedding(dim, m, n=None, t=4):
      m, n, t, target_edges = _chimera_input(m, n, t, None)
      indexer = dnx.generators.chimera.chimera_coordinates(m, n, t)
      dim = list(dim)
      num_dim = len(dim)
      if num_dim == 1:
          def _key(row, col, aisle): return row
          dim.extend([1, 1])
      elif num_dim == 2:
          def _key(row, col, aisle): return row, col
          dim.append(1)
      elif num_dim == 3:
          def _key(row, col, aisle): return row, col, aisle
      else:
          raise ValueError("find_grid_embedding supports between one and three dimensions")
      rows, cols, aisles = dim
      if rows > m or cols > n or aisles > t:
          msg = ("the largest grid that find_grid_embedding can fit in a ({}, {}, {}) Chimera-lattice "
                 "is {}x{}x{}; given grid is {}x{}x{}").format(m, n, t, m, n, t, rows, cols, aisles)
          raise ValueError(msg)
      return {_key(row, col, aisle): [indexer.int((row, col, 0, aisle)), indexer.int((row, col, 1, aisle))]
              for row in range(dim[0]) for col in range(dim[1]) for aisle in range(dim[2])}