fix:(review) removed a unnecessary interface, and added a javadoc comment.

Author: sttk

src/main/java/com/github/sttk/cliargs/Cmd.java

@@ -135,7 +135,9 @@ public List<OptCfg> optCfgs() {
   }
 
   /**
-   * {@inheritDoc}
+   * Get the content string of this object.
+   *
+   * @return The content string of this object.
    */
   @Override
   public String toString() {

src/main/java/com/github/sttk/cliargs/OptCfg.java

@@ -372,20 +372,6 @@ static Param validator(Validator validator) {
     }
   }
 
-  /**
-   * Is the functional interface to process option arguments when the option has been parsed.
-   */
-  @FunctionalInterface
-  public interface OnParsed {
-    /**
-     * Processes the option arguments.
-     *
-     * @param optArgs  The list of the option arguments.
-     * @throws FailToSetOptionStoreField  If failed to set the field value of the option store.
-     */
-    void process(List<String> optArgs) throws FailToSetOptionStoreField;
-  }
-
   /**
    * Makes an {@link OptCfg} array from the fields opt the option store with the annotation
    * {@link Opt}.