added skipFastLockRound paramter to StreamTransactionOptions (#574)

Author: rashtao

core/src/main/java/com/arangodb/model/StreamTransactionOptions.java

@@ -36,6 +36,7 @@ public final class StreamTransactionOptions {
     private Boolean allowImplicit;
     @JsonIgnore
     private Boolean allowDirtyRead;
+    private Boolean skipFastLockRound;
 
     public StreamTransactionOptions() {
         super();
@@ -148,4 +149,25 @@ public StreamTransactionOptions allowDirtyRead(final Boolean allowDirtyRead) {
         return this;
     }
 
+    public Boolean getSkipFastLockRound() {
+        return skipFastLockRound;
+    }
+
+    /**
+     * @param skipFastLockRound Whether to disable fast locking for write operations. Skipping the fast lock round can
+     *                          be faster overall if there are many concurrent Stream Transactions queued that all try
+     *                          to lock the same collection exclusively. It avoids deadlocking and retrying which can
+     *                          occur with the fast locking by guaranteeing a deterministic locking order at the expense
+     *                          of each actual locking operation taking longer.
+     *                          Fast locking should not be skipped for read-only Stream Transactions because it degrades
+     *                          performance if there are no concurrent transactions that use exclusive locks on the same
+     *                          collection.
+     *                          Default: {@code false}
+     * @return options
+     * @since ArangoDB 3.12.0
+     */
+    public StreamTransactionOptions skipFastLockRound(final Boolean skipFastLockRound) {
+        this.skipFastLockRound = skipFastLockRound;
+        return this;
+    }
 }