TiCommand is used to inherit from org.apache.spark.sql.execution.command.RunnableCommand
CHECK Spark org.apache.spark.sql.execution.command.DescribeTableCommand
CHECK Spark org.apache.spark.sql.execution.command.SetDatabaseCommand
CHECK Spark org.apache.spark.sql.execution.command.ShowColumnsCommand
CHECK Spark org.apache.spark.sql.execution.command.ShowDatabasesCommand
CHECK Spark org.apache.spark.sql.execution.command.ShowTablesCommand