How to use the cassandra-driver.client function in cassandra-driver

auditLogger.transition = function (originalAgentDataId, meta, agentName, agentConversation, transition, data) {
      var userName = getUserName(meta.user)
      cql.client.execute('insert into conversationTransitionCausedBy(conversationId,toConversationId,time,userName,agentName,agentStateName,eventName,json) VALUES (?,?,?,?,?,?,?,?)',
        [
          originalAgentDataId || 'null',
          meta.agentDataId || 'null',
          new Date(),
          userName,
          agentName,
          agentConversation.state,
          transition.causeName,
          JSON.stringify(data)
        ],
        {
          prepare: true
        },
        function (err) {
          if (err) {
            logger.error('transition', err.stack, meta.user)

function useKeyspace (next) {
        cql.client.keyspace = keyspace
        var query = 'USE ' + keyspace
        cql.client.execute(query, next)
      },
      function createTables (next) {

function useKeyspace (next) {
        cql.client.keyspace = keyspace
        var query = 'USE ' + keyspace
        cql.client.execute(query, next)
      },
      function createTables (next) {