def to_data only_props: false, **kwds
      hash = super **kwds
      
      unless only_props
        each do |key, value|
          # Data uses **string** keys
          key = key.to_s
          
          # See if the key is missing
          unless hash.key?( key.to_s )
            # It is, so let's fill it in
            
            # If value knows how to be data, do that
            value = value.to_data if value.respond_to?( :to_data )
            
            # Set the key/value pair
            hash[key] = value
          end
        end
      end
      
      hash
    end
def to_data only_props: false, **kwds
      hash = super **kwds
      
      unless only_props
        each do |key, value|
          # Data uses **string** keys
          key = key.to_s
          
          # See if the key is missing
          unless hash.key?( key.to_s )
            # It is, so let's fill it in
            
            # If value knows how to be data, do that
            value = value.to_data if value.respond_to?( :to_data )
            
            # Set the key/value pair
            hash[key] = value
          end
        end
      end
      
      hash
    end
#initialize_props
 Override {NRSER::Props::InstanceMethods#to_data} to handle non-prop
 values in the {NRSER::Stash}.

 @param [Boolean] only_props
   When `true` only prop values will be added to the data hash.

   Otherwise, any non-prop keys and vales will be added as well
   (default behavior).

 @param [Hash] kwds
   See {NRSER::Props::InstanceMethods#to_data}.

 @return (see NRSER::Props::InstanceMethods#to_data)