Add merging and matching of parsed BlockData

By: md_5 <git@md-5.net>

paper-api/src/main/java/org/bukkit/block/data/BlockData.java

@@ -21,6 +21,41 @@ public interface BlockData extends Cloneable {
      */
     String getAsString();
 
+    /**
+     * Merges all explicitly set states from the given data with this BlockData.
+     * <br>
+     * Note that the given data MUST have been created from one of the String
+     * parse methods, e.g. {@link Server#createBlockData(java.lang.String)} and
+     * not have been subsequently modified.
+     * <br>
+     * Note also that the block types must match identically.
+     *
+     * @param data the data to merge from
+     * @return a new instance of this blockdata with the merged data
+     * @deprecated draft API
+     */
+    @Deprecated
+    BlockData merge(BlockData data);
+
+    /**
+     * Checks if the specified BlockData matches this block data.
+     * <br>
+     * The semantics of this method are such that for manually created or
+     * modified BlockData it has the same effect as
+     * {@link Object#equals(java.lang.Object)}, whilst for parsed data (that to
+     * which {@link #merge(org.bukkit.block.data.BlockData)} applies, it will
+     * return true when the type and all explicitly set states match.
+     * <br>
+     * <b>Note that these semantics mean that a.matches(b) may not be the same
+     * as b.matches(a)</b>
+     *
+     * @param data the data to match against (normally a parsed constant)
+     * @return if there is a match
+     * @deprecated draft API
+     */
+    @Deprecated
+    boolean matches(BlockData data);
+
     /**
      * Returns a copy of this BlockData.
      *