Switched form set o list

src/main/java/org/gcube/accounting/analytics/persistence/AccountingPersistenceBackendQuery.java

@@ -72,7 +72,7 @@ public interface AccountingPersistenceBackendQuery {
 	 * If the list contains more than one filter with the same key an Exception is thrown 
 	 * when trying to query.
 	 */
-	public void setFilters(Set<Filter> filters);
+	public void setFilters(List<Filter> filters);
 	
 	/**
 	 * Query the persistence obtaining a Map where the date is the key and the

src/main/java/org/gcube/accounting/analytics/persistence/AccountingPersistenceQuery.java

@@ -60,7 +60,7 @@ public class AccountingPersistenceQuery implements AccountingPersistenceBackendQ
 	protected TemporalConstraint temporalConstraint;
 	
 	protected Set<String> contexts;
-	protected Set<Filter> filters;
+	protected List<Filter> filters;
 	
 	protected ObjectMapper objectMapper;
 	
@@ -90,7 +90,7 @@ public class AccountingPersistenceQuery implements AccountingPersistenceBackendQ
 	}
 	
 	@Override
-	public void setFilters(Set<Filter> filters) {
+	public void setFilters(List<Filter> filters) {
 		this.filters = filters;
 		accountingPersistenceBackendQuery.setFilters(filters);
 	}