Fix javadoc
diff --git a/src/main/java/org/apache/datasketches/hll/BaseHllSketch.java b/src/main/java/org/apache/datasketches/hll/BaseHllSketch.java
index 760b97e..844f328 100644
--- a/src/main/java/org/apache/datasketches/hll/BaseHllSketch.java
+++ b/src/main/java/org/apache/datasketches/hll/BaseHllSketch.java
@@ -203,7 +203,7 @@
/**
* Serializes this sketch as a byte array in compact form. The compact form is smaller in size
* than the updatable form and read-only. It can be used in union operations as follows:
- * <pre>
+ * <pre>{@code
* Union union; HllSketch sk, sk2;
* int lgK = 12;
* sk = new HllSketch(lgK, TgtHllType.HLL_4); //can be 4, 6, or 8
@@ -218,7 +218,7 @@
* sk2 = HllSketch.heapify(arr);
* //OR, if used in an off-heap environment:
* sk2 = HllSketch.heapify(Memory.wrap(arr));
- * </pre>
+ * }</pre>
*
* <p>The sketch "wrapping" operation skips actual deserialization thus is quite fast. However,
* any attempt to update the derived HllSketch will result in a Read-only exception.
@@ -231,7 +231,7 @@
* the compact form. The use of this form is primarily in environments that support updating
* sketches in off-heap memory. If the sketch is constructed using HLL_8, sketch updating and
* union updating operations can actually occur in WritableMemory, which can be off-heap:
- * <pre>
+ * <pre>{@code
* Union union; HllSketch sk;
* int lgK = 12;
* sk = new HllSketch(lgK, TgtHllType.HLL_8) //must be 8
@@ -240,7 +240,7 @@
* WritableMemory wmem = WritableMemory.wrap(arr);
* //...
* union = Union.writableWrap(wmem); //no deserialization!
- * </pre>
+ * }</pre>
* @return this sketch as an updatable byte array.
*/
public abstract byte[] toUpdatableByteArray();
