About: http://webisa.webdatacommons.org/170005493

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	If it still nulls the birthdays, then perhaps birthday is a class that sortUsingDescriptors does not know how to sort.
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com