About: http://webisa.webdatacommons.org/101682603

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 can also add a check for is_array at line 4 of the last snippet before is_empty (where you are saying the error is generated), and move forward only if the variable is an array.
http://www.w3.org/ns/prov#wasQuotedFrom	rahulsingla.com