code: protected boolean equivalentClaims(Claim claim1, Claim claim2) {
  		return claim1.getMainSnak().equals(claim2.getMainSnak())
  				&& isSameSnakSet(claim1.getAllQualifiers(),
  						claim2.getAllQualifiers());
  	}
docs: Checks if two claims are equivalent in the sense that they have the same
  main snak and the same qualifiers, but possibly in a different order.
  
  @param claim1
  @param claim2
  @return true if claims are equivalent