About: http://webisa.webdatacommons.org/377748351

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	You will definitely get the error you see if you compare for example apples" with an actual id, right now you are comparing it to an empty string which is also an invalid id.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com