MERGE (product1:Product {name:'product1'})
MERGE (reviewer1:Reviewer {name:'reviewer1'})
MERGE (reviewer1)-[:Reviewed {name: 'reviewed'}]-(product1)
MERGE (reviewer2:Reviewer {name:'reviewer2'})
MERGE (reviewer2)-[:Reviewed {name: 'reviewed'}]-(product1)
MERGE (reviewer3:Reviewer {name:'reviewer3'})
MERGE (reviewer3)-[:Reviewed {name: 'reviewed'}]-(product1)
MERGE (reviewer7:Reviewer {name:'reviewer7'})
MERGE (reviewer7)-[:Reviewed {name: 'reviewed'}]-(product1)
[...]