You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: explain_support.rb
    path of file: ./repos/activerecord-jdbc-adapter/lib/arjdbc/hsqldb
    
    the code of the file until where you have to start completion: module ArJdbc
  module HSQLDB
    module
    
      def supports_explain?; true; end

      def explain(arel, binds = [])
        sql = "EXPLAIN PLAN FOR #{to_sql(arel, binds)}"
        raw_result = exec_query_raw(sql, "EXPLAIN", binds)
        # HSQLDB's SqlTool just prints it as it comes :
        #
        #  sql> EXPLAIN PLAN FOR SELECT * FROM entries JOIN users on ... ;
        #
        # isDistinctSelect=[false]
        # isGrouped=[false]
        # isAggregated=[false]
        # columns=[  COLUMN: PUBLIC.ENTRIES.ID
        #  not nullable  COLUMN: PUBLIC.ENTRIES.TITLE
        #  nullable  COLUMN: PUBLIC.ENTRIES.UPDATED_ON
        #  nullable  COLUMN: PUBLIC.ENTRIES.CONTENT
        #  nullable  COLUMN: PUBLIC.ENTRIES.RATING
        #  nullable  COLUMN: PUBLIC.ENTRIES.USER_ID
        #  nullable  COLUMN: PUBLIC.USERS.ID
        #  not nullable  COLUMN: PUBLIC.USERS.LOGIN
        #  nullable
        # ]
        # ...
        # PARAMETERS=[]
        # SUBQUERIES[]
        #
        raw_result.map!(&:values)
        raw_result.join("\n")
      end
    end