@on_by_default.setter<EOL><INDENT>def on_by_default(self, on_by_default):<DEDENT>
self._on_by_default = on_by_default<EOL>
Sets the on_by_default of this CatalogModifierOverride.
If `true`, this [CatalogModifier](#type-catalogmodifier) should be selected by default for this [CatalogItem](#type-catalogitem).

:param on_by_default: The on_by_default of this CatalogModifierOverride.
:type: bool