Add a select sub-traversal to the traversal library.

gremlin-objects/src/main/java/org/apache/tinkerpop/gremlin/object/traversal/ElementTo.java

@@ -81,4 +81,14 @@ interface Any extends SubTraversal<
       java.lang.Object> {
 
   }
+
+  /**
+   * A function denoting a {@code GraphTraversal} that starts at elements, and ends in maps.
+   */
+  @FunctionalInterface
+  @SuppressWarnings("PMD.ShortClassName")
+  interface Map extends SubTraversal<
+      org.apache.tinkerpop.gremlin.structure.Element,
+      java.util.Map<java.lang.String, java.lang.Object>> {
+  }
 }

gremlin-objects/src/main/java/org/apache/tinkerpop/gremlin/object/traversal/library/Select.java

@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tinkerpop.gremlin.object.traversal.library;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import lombok.Data;
+import org.apache.tinkerpop.gremlin.object.traversal.ElementTo;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
+import org.apache.tinkerpop.gremlin.structure.Element;
+
+/**
+ * {@link Select} applies the ${link GraphTraversal#count} step on the current traversal.
+ *
+ * @author Karthick Sankarachary
+ */
+@Data
+public class Select implements ElementTo.Map {
+
+  private String selectKey1;
+  private String selectKey2;
+  private List<String> otherSelectKeys;
+
+  @SuppressWarnings("PMD.ShortMethodName")
+  public static Select of(String... aliases) {
+    Select select = new Select();
+    if (aliases.length > 0) {
+      select.selectKey1 = aliases[0];
+    }
+    if (aliases.length > 1) {
+      select.selectKey2 = aliases[1];
+    }
+    if (aliases.length > 2) {
+      select.otherSelectKeys = Arrays.asList(aliases);
+      select.otherSelectKeys.remove(0);
+      select.otherSelectKeys.remove(0);
+    } else {
+      select.otherSelectKeys = new ArrayList<>();
+    }
+    return select;
+  }
+
+
+  @Override
+  public GraphTraversal<Element, Map<String, Object>> apply(
+      GraphTraversal<Element, Element> traversal) {
+    GraphTraversal<Element, Map<String, Object>> selectTraversal;
+    if (selectKey2 == null) {
+      selectTraversal = traversal.select(selectKey1);
+    } else {
+      selectTraversal =
+          traversal.select(selectKey1, selectKey2, otherSelectKeys.toArray(new String[] {}));
+    }
+    if (selectKey1 != null) {
+      selectTraversal.by();
+    }
+    if (selectKey2 != null) {
+      selectTraversal.by();
+    }
+    otherSelectKeys.forEach(otherSelectKey -> {
+      selectTraversal.by();
+    });
+    return selectTraversal;
+  }
+}