#NEWLINE# def get_field_value( self , key , default = None ) : #NEWLINE# #INDENT# 'Retrieves the value in the payload field if the field exists, otherwise returns the default.\n\n    :API: public\n    ' #NEWLINE# if ( key in self . _fields ) : #NEWLINE# #INDENT# payload_field = self . _fields [ key ] #NEWLINE# if payload_field : #NEWLINE# #INDENT# return payload_field . value #NEWLINE# #UNINDENT# #UNINDENT# return default