def join_flags(flags,
                   separator: ObjectInspector.configuration.flags_separator)
      the_flags = Array(flags).tap(&:compact!)
      the_flags.join(separator) if the_flags.any?
    end
def join_flags(flags,
                   separator: ObjectInspector.configuration.flags_separator)
      the_flags = Array(flags).tap(&:compact!)
      the_flags.join(separator) if the_flags.any?
    end
Join the passed-in flags with the passed in separator.

 @param flags [Array<#to_s>]
 @param separator [#to_s] (ObjectInspector.configuration.flags_separator)