Add PostgresqlResult.filter(…) overrides to return PostgresqlResult instead of Result.

[resolves #602]

Signed-off-by: Mark Paluch <[email protected]>

Author: mp911de

src/main/java/io/r2dbc/postgresql/api/PostgresqlResult.java

@@ -23,6 +23,7 @@
 import reactor.core.publisher.Mono;
 
 import java.util.function.BiFunction;
+import java.util.function.Predicate;
 
 /**
  * A {@link Result} representing the results of a query against a PostgreSQL database.
@@ -41,4 +42,10 @@ public interface PostgresqlResult extends Result {
     @Override
     <T> Flux<T> map(BiFunction<Row, RowMetadata, ? extends T> mappingFunction);
 
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    PostgresqlResult filter(Predicate<Segment> predicate);
+
 }

src/test/java/io/r2dbc/postgresql/api/MockPostgresqlResult.java

@@ -16,7 +16,6 @@
 
 package io.r2dbc.postgresql.api;
 
-import io.r2dbc.spi.Result;
 import io.r2dbc.spi.Row;
 import io.r2dbc.spi.RowMetadata;
 import org.reactivestreams.Publisher;
@@ -56,7 +55,7 @@ public <T> Flux<T> map(BiFunction<Row, RowMetadata, ? extends T> mappingFunction
     }
 
     @Override
-    public Result filter(Predicate<Segment> filter) {
+    public PostgresqlResult filter(Predicate<Segment> filter) {
         throw new UnsupportedOperationException();
     }