Executes the given command at some time in the future. The command
may execute in a new thread, in a pooled thread, or in the calling
thread, at the discretion of the {@code Executor} implementation.
@param command the runnable task
@throws RejectedExecutionException if this task cannot be
accepted for execution
@throws NullPointerException if command is null
Executes the given command at some time in the future. The command may execute in a new thread, in a pooled thread, or in the calling thread, at the discretion of the {@code Executor} implementation.
@param command the runnable task @throws RejectedExecutionException if this task cannot be accepted for execution @throws NullPointerException if command is null