code: def _bulk_to_linear(M, N, L, qubits):
      "Converts a list of chimera coordinates to linear indices."
      return [2 * L * N * x + 2 * L * y + L * u + k for x, y, u, k in qubitsf _bulk_to_linear(M, N, L, qubits):
      "Converts a list of chimera coordinates to linear indices."
      return [2 * L * N * x + 2 * L * y + L * u + k for x, y, u, k in qubits]
docs: Converts a list of chimera coordinates to linear indices.