Pyright expects generic type parameters to be specified for the
Attribute class, otherwise it treats the type as Unknown which can
trigger reportUnknownMemberType errors.
This can be solved by using a generic type parameter for these methods
which also has the benefit of making sure that the value parameter has
the correct type for the attribute.
In some cases, a new local `value_as_bytes` variable is needed to avoid
type errors and makes the code less confusing by not overwriting the
original `value` variable.
David Lechner
baa5257780