def []=(name, entry)
      warn "#{self.class}#[]= is deprecated. Use #{self.class}#<< instead: #{caller.first}"
      raise "#{entry.class} is not added with the correct name" unless name && name.to_s == entry.name.to_s
      self << entry
      entry
    end
def []=(name, entry)
      warn "#{self.class}#[]= is deprecated. Use #{self.class}#<< instead: #{caller.first}"
      raise "#{entry.class} is not added with the correct name" unless name && name.to_s == entry.name.to_s
      self << entry
      entry
    end
Make sure that entry is part of this PropertySet

 @param [#to_s] name
 @param [#name] entry

 @return [#name]
   the entry that is now part of this PropertySet

 @api semipublic