Add Duration methods to TaskBuilder (#445)

api/src/main/java/com/velocitypowered/api/scheduler/Scheduler.java

@@ -7,6 +7,7 @@
 
 package com.velocitypowered.api.scheduler;
 
+import java.time.Duration;
 import java.util.concurrent.TimeUnit;
 import org.checkerframework.common.value.qual.IntRange;
 
@@ -38,6 +39,16 @@ public interface Scheduler {
      */
     TaskBuilder delay(@IntRange(from = 0) long time, TimeUnit unit);
 
+    /**
+     * Specifies that the task should delay its execution by the specified amount of time.
+     *
+     * @param duration the duration of the delay
+     * @return this builder, for chaining
+     */
+    default TaskBuilder delay(Duration duration) {
+      return delay(duration.toMillis(), TimeUnit.MILLISECONDS);
+    }
+
     /**
      * Specifies that the task should continue running after waiting for the specified amount, until
      * it is cancelled.
@@ -48,6 +59,17 @@ public interface Scheduler {
      */
     TaskBuilder repeat(@IntRange(from = 0) long time, TimeUnit unit);
 
+    /**
+     * Specifies that the task should continue running after waiting for the specified amount, until
+     * it is cancelled.
+     *
+     * @param duration the duration of the delay
+     * @return this builder, for chaining
+     */
+    default TaskBuilder repeat(Duration duration) {
+      return repeat(duration.toMillis(), TimeUnit.MILLISECONDS);
+    }
+
     /**
      * Clears the delay on this task.
      *