From c3aee0a6bdca4612320e10d636d175673d48060f Mon Sep 17 00:00:00 2001
From: Gabor Szadovszky <gabor@apache.org>
Date: Wed, 9 Jan 2019 11:40:32 +0100
Subject: [PATCH] PARQUET-1489: Insufficient documentation for
 UserDefinedPredicate.keep(T)

---
 .../parquet/filter2/predicate/UserDefinedPredicate.java      | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/parquet-column/src/main/java/org/apache/parquet/filter2/predicate/UserDefinedPredicate.java b/parquet-column/src/main/java/org/apache/parquet/filter2/predicate/UserDefinedPredicate.java
index 05365b9918..e5103b4ae7 100644
--- a/parquet-column/src/main/java/org/apache/parquet/filter2/predicate/UserDefinedPredicate.java
+++ b/parquet-column/src/main/java/org/apache/parquet/filter2/predicate/UserDefinedPredicate.java
@@ -40,8 +40,11 @@ public UserDefinedPredicate() { }
 
   /**
    * Return true to keep the record with this value, false to drop it.
+   * <p>
+   * This method shall handle {@code null} values returning whether this user defined predicate accepts {@code null}
+   * values or not.
    *
-   * @param value a value
+   * @param value a value (might be {@code null})
    * @return true to keep the record with the value, false to drop it
    */
   public abstract boolean keep(T value);