doc: mark ExplainPrettyPrinter class as private
doc: mark ExplainPrettyPrinter class as private

kares/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,bruceadams/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,kares/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,jruby/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter,keeguon/activerecord-jdbc-adapter