index_name_for_remove

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 583
        def index_name_for_remove(table_name, options = {})
          index_name = index_name(table_name, options)

          unless index_name_exists?(table_name, index_name, true)
            raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"
          end

          index_name
        end