WordPress TinyMCE paste as plain text

<?php
/**
 * Replaces plugin for pasting as plain text on TinyMCE.
 *
 * Adapted form http://wordpress.org/plugins/paste-as-plain-text/
 */
 
 add_action( 'admin_init', 'BRR2025_paste_plain_init' );
 
 function BRR2025_paste_plain_init() {
   
	add_filter( 'tiny_mce_before_init', 'BRR2025_force_paste_as_plain_text' );
	add_filter( 'teeny_mce_before_init', 'BRR2025_force_paste_as_plain_text' );
	add_filter( 'teeny_mce_plugins', 'BRR2025_load_paste_in_teeny' );
	add_filter( 'mce_buttons_2', 'BRR2025_remove_paste_plain_text_button' );
  
 }  
  
	function BRR2025_force_paste_as_plain_text( $mceInit ) {

		global $tinymce_version;

		if ( $tinymce_version[0] < 4 ) {
			$mceInit[ 'paste_text_sticky' ] = true;
			$mceInit[ 'paste_text_sticky_default' ] = true;
		} else {
			$mceInit[ 'paste_as_text' ] = true;
		}

		return $mceInit;
	}

	function BRR2025_load_paste_in_teeny( $plugins ) {

		return array_merge( $plugins, (array) 'paste' );

	}

	function BRR2025_remove_paste_plain_text_button( $buttons ) {

		if( ( $key = array_search( 'pastetext', $buttons ) ) !== false ) {
			unset( $buttons[ $key ] );
		}

		return $buttons;

	}