diff --git a/solr/core/src/java/org/apache/solr/search/facet/FacetParser.java b/solr/core/src/java/org/apache/solr/search/facet/FacetParser.java
index 854f353bcd2..355962f9088 100644
--- a/solr/core/src/java/org/apache/solr/search/facet/FacetParser.java
+++ b/solr/core/src/java/org/apache/solr/search/facet/FacetParser.java
@@ -139,8 +139,18 @@ public Object parseFacetOrStat(String key, Object o) throws SyntaxError {
     return parseFacetOrStat(key, type, args);
   }
 
+  /** Extension point for custom facets and aggs */
   public interface ParseHandler {
-    Object doParse(FacetParser<?> parent, String key, Object args) throws SyntaxError;
+    /**
+     * Parse a facet or stat based on the type and arguments provided.
+     *
+     * @param parent parent parser
+     * @param key facet or agg key
+     * @param args value of facet to parse
+     * @return either FacetRequest of AggValueSource subclass instance
+     * @throws SyntaxError on unexpected values
+     */
+    Object parse(FacetParser<?> parent, String key, Object args) throws SyntaxError;
   }
 
   private static final Map<String, ParseHandler> REGISTERED_TYPES = new ConcurrentHashMap<>();
@@ -162,7 +172,7 @@ public static void registerParseHandler(String type, ParseHandler parseHandler)
   public Object parseFacetOrStat(String key, String type, Object args) throws SyntaxError {
     ParseHandler parseHandler = REGISTERED_TYPES.get(type);
     if (parseHandler != null) {
-      return parseHandler.doParse(this, key, args);
+      return parseHandler.parse(this, key, args);
     }
 
     throw err("Unknown facet or stat. key=" + key + " type=" + type + " args=" + args);
diff --git a/solr/core/src/test/org/apache/solr/search/function/CustomParseHandlerTest.java b/solr/core/src/test/org/apache/solr/search/function/CustomParseHandlerTest.java
index 0c906ff9484..0ecd3793d68 100644
--- a/solr/core/src/test/org/apache/solr/search/function/CustomParseHandlerTest.java
+++ b/solr/core/src/test/org/apache/solr/search/function/CustomParseHandlerTest.java
@@ -1,47 +1,62 @@
+/*
+ * 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.solr.search.function;
 
+import java.util.Collections;
+import java.util.Map;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.handler.component.ResponseBuilder;
 import org.apache.solr.request.SolrQueryRequest;
 import org.apache.solr.response.SolrQueryResponse;
-import org.apache.solr.search.SyntaxError;
 import org.apache.solr.search.facet.FacetField;
 import org.apache.solr.search.facet.FacetParser;
 import org.apache.solr.search.facet.FacetRequest;
 import org.junit.BeforeClass;
 
-import java.util.Collections;
-import java.util.Map;
-
-
 public class CustomParseHandlerTest extends SolrTestCaseJ4 {
 
-    public static final FacetField FACET_FIELD_STUB = new FacetField();
-
-    static class CustomParseHandler implements FacetParser.ParseHandler {
-        @Override
-        public Object doParse(FacetParser<?> parent, String key, Object args) {
-            assertEquals("arg", args);
-            return FACET_FIELD_STUB;
-        }
-    }
-
-    @BeforeClass
-    public static void beforeClass() throws Exception {
-        initCore("solrconfig.xml", "schema.xml");
-    }
+  public static final FacetField FACET_FIELD_STUB = new FacetField();
 
+  static class CustomParseHandler implements FacetParser.ParseHandler {
     @Override
-    public void setUp() throws Exception {
-        super.setUp();
-        FacetParser.registerParseHandler("custom", new CustomParseHandler());
-    }
-
-    public void testCustomParseHandler() {
-        SolrQueryRequest req = req();
-        ResponseBuilder rsp = new ResponseBuilder(req, new SolrQueryResponse(), Collections.emptyList());
-
-        FacetRequest facetRequest = FacetRequest.parse(rsp.req, Map.of("bogus",Map.of("custom","arg")));
-        assertEquals(FACET_FIELD_STUB, facetRequest.getSubFacets().get("bogus"));
+    public Object parse(FacetParser<?> parent, String key, Object args) {
+      assertEquals("arg", args);
+      return FACET_FIELD_STUB;
     }
+  }
+
+  @BeforeClass
+  public static void beforeClass() throws Exception {
+    initCore("solrconfig.xml", "schema.xml");
+  }
+
+  @Override
+  public void setUp() throws Exception {
+    super.setUp();
+    FacetParser.registerParseHandler("custom", new CustomParseHandler());
+  }
+
+  public void testCustomParseHandler() {
+    SolrQueryRequest req = req();
+    ResponseBuilder rsp =
+        new ResponseBuilder(req, new SolrQueryResponse(), Collections.emptyList());
+
+    FacetRequest facetRequest =
+        FacetRequest.parse(rsp.req, Map.of("bogus", Map.of("custom", "arg")));
+    assertEquals(FACET_FIELD_STUB, facetRequest.getSubFacets().get("bogus"));
+  }
 }