Use tokenizer's settings in a setting of SynonymTokenFilter

In the following index setting, synonymTest uses own settings, not bigramTokenizer's one (synonymTest does not use min_gram and max_gram). I think that it's better to use bigramTokenizer's setting.

    curl -XPUT localhost:9200/test -d '{
      "settings" : {
        "analysis" : {
          "analyzer" : {
            "bigram_analyzer" : {
              "type" : "custom",
              "tokenizer" : "bigramTokenizer",
              "filter" : ["synonymTest"]
            }
          },
          "tokenizer" : {
              "bigramTokenizer" : {
              "type" : "ngram",
              "min_gram" : 2,
              "max_gram" : 2
            }
          },
          "filter" : {
            "synonymTest" : {
              "type" : "synonym",
              "synonyms_path" : "synonym.txt",
              "tokenizer" : "bigramTokenizer"
            }
          }
        }
      }
    }'