About: http://webisa.webdatacommons.org/291018964

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	Interface is a contract that your implementing class must full fill.in your case your implementing class Block should implement the following methods to full fill the contract.
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com