Change QueryPlanInit to support thresholdMicros per hash

Effectively means that we can provide a thresholdMicros per query plan hash [for the plans that we want collected]

Author: rbygrave

ebean-api/src/main/java/io/ebean/meta/QueryPlanInit.java

@@ -81,8 +81,8 @@ public void remove(String hash) {
    * Return the threshold in micros to use for the given hash.
    */
   public long thresholdMicros(String hash) {
-    long threshold = hashes.get(hash);
-    return threshold < 1 ? defaultThresholdMicros : threshold;
+    Long threshold = hashes.get(hash);
+    return threshold == null || threshold < 1 ? defaultThresholdMicros : threshold;
   }
 
   /**

ebean-api/src/test/java/io/ebean/meta/QueryPlanInitTest.java

@@ -36,6 +36,7 @@ void addWithThresholds() {
     assertThat(init.includeHash("xJunk")).isFalse();
     assertThat(init.includeHash("xOne")).isTrue();
     assertThat(init.includeHash("xTwo")).isTrue();
+    assertThat(init.thresholdMicros("xJunk")).isEqualTo(1000L);
     assertThat(init.thresholdMicros("xOne")).isEqualTo(1000L);
     assertThat(init.thresholdMicros("xTwo")).isEqualTo(2000L);
   }