code: private void dropKeyspaceOrCFs() throws InvalidRequestException, SchemaDisagreementException, TException, Exception
      {
          if (createdKeyspaces.contains(databaseName))// drop if created during
                                                      // create-drop call.
          {
              cassandra_client.system_drop_keyspace(databaseName);
          }
          else
          {
              cassandra_client.set_keyspace(databaseName);
              for (TableInfo tableInfo : tableInfos)
              {
                  dropColumnFamily(tableInfo);
              }
          }
      }
docs: Drop keyspace or c fs.
  
  @throws InvalidRequestException
  the invalid request exception
  @throws SchemaDisagreementException
  the schema disagreement exception
  @throws TException
  the t exception
  @throws Exception
  the exception