code: def _huffman_encode_char(cls, c):
          # type: (Union[str, EOS]) -> Tuple[int, int]
          
          if isinstance(c, EOS):
              return cls.static_huffman_code[-1]
          else:
              assert(isinstance(c, int) or len(c) == 1)
          return cls.static_huffman_code[orb(c)]
docs: huffman_encode_char assumes that the static_huffman_tree was
          previously initialized
  
          @param str|EOS c: a symbol to encode
          @return (int, int): the bitstring of the symbol and its bitlength
          @raise AssertionError