Allow assigning particles to attributes (via AssociatedParticle, but the Python code nevers sees this class).
Upon deserialization, unparsed attributes are now represented with the type UnparsedAttribute. Users can convert it to a real attribute with the astype method.
Allow assigning particles to attributes (via AssociatedParticle, but the Python code nevers sees this class).
Upon deserialization, unparsed attributes are now represented with the type UnparsedAttribute. Users can convert it to a real attribute with the astype method.