def commit_chain(chain_names, content)
      params = { 'CommitChainMsg' => get_chain_commit(chain_names, content) }
      raw_post "/v1/commit-chain/", params.to_json, content_type: :json
    end
def commit_chain(chain_names, content)
      params = { 'CommitChainMsg' => get_chain_commit(chain_names, content) }
      raw_post "/v1/commit-chain/", params.to_json, content_type: :json
    end
Params:
 chain_names - chain name combination, must be unique globally. It's
               first entry's external ids actually.
 content     - content of first entry