in lib/wit.rb [129:134]
def post_entities_keywords_synonyms(entity, keyword, payload)
payload = payload.map {|k, v| [(k.to_sym rescue k), v]}.to_h.reject{ |k| ![:synonym].include?(k) }
validate_payload payload
req(logger,@access_token, Net::HTTP::Post, "/entities/#{URI.encode(entity)}/keywords/#{URI.encode(keyword)}/synonyms", {}, payload)
end