How to use the @pixi/settings.settings.PREFER_ENV function in @pixi/settings

contextChange()
    {
        const gl = this.renderer.gl;

        if (settings.PREFER_ENV === ENV.WEBGL_LEGACY)
        {
            this.MAX_TEXTURES = 1;
        }
        else
        {
            // step 1: first check max textures the GPU can handle.
            this.MAX_TEXTURES = Math.min(
                gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS),
                settings.SPRITE_MAX_TEXTURES);

            // step 2: check the maximum number of if statements the shader can have too..
            this.MAX_TEXTURES = checkMaxIfStatementsInShader(
                this.MAX_TEXTURES, gl);
        }

        this._shader = this.shaderGenerator.generateShader(this.MAX_TEXTURES);

contextChange()
    {
        const gl = this.renderer.gl;

        if (settings.PREFER_ENV === ENV.WEBGL_LEGACY)
        {
            this.MAX_TEXTURES = 1;
        }
        else
        {
            // step 1: first check max textures the GPU can handle.
            this.MAX_TEXTURES = Math.min(
                gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS),
                settings.SPRITE_MAX_TEXTURES);

            // step 2: check the maximum number of if statements the shader can have too..
            this.MAX_TEXTURES = checkMaxIfStatementsInShader(
                this.MAX_TEXTURES, gl);
        }

        this._shader = this.shaderGenerator.generateShader(this.MAX_TEXTURES);

contextChange()
    {
        const gl = this.renderer.gl;

        if (settings.PREFER_ENV === ENV.WEBGL_LEGACY)
        {
            this.MAX_TEXTURES = 1;
        }
        else
        {
            // step 1: first check max textures the GPU can handle.
            this.MAX_TEXTURES = Math.min(gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS), settings.SPRITE_MAX_TEXTURES);

            // step 2: check the maximum number of if statements the shader can have too..
            this.MAX_TEXTURES = checkMaxIfStatementsInShader(this.MAX_TEXTURES, gl);
        }

        // generate generateMultiTextureProgram, may be a better move?
        this.shader = generateMultiTextureShader(gl, this.MAX_TEXTURES);

        // we use the second shader as the first one depending on your browser may omit aTextureId

* The maximum support for using WebGL. If a device does not
 * support WebGL version, for instance WebGL 2, it will still
 * attempt to fallback support to WebGL 1. If you want to
 * explicitly remove feature support to target a more stable
 * baseline, prefer a lower environment.
 *
 * Due to {@link https://bugs.chromium.org/p/chromium/issues/detail?id=934823|bug in chromium}
 * we disable webgl2 by default for all non-apple mobile devices.
 *
 * @static
 * @name PREFER_ENV
 * @memberof PIXI.settings
 * @type {number}
 * @default PIXI.ENV.WEBGL2
 */
settings.PREFER_ENV = isMobile.any ? ENV.WEBGL : ENV.WEBGL2;

/**
 * If set to `true`, Textures and BaseTexture objects stored
 * in the caches ({@link PIXI.utils.TextureCache TextureCache} and
 * {@link PIXI.utils.BaseTextureCache BaseTextureCache}) can *only* be
 * used when calling {@link PIXI.Texture.from Texture.from} or
 * {@link PIXI.BaseTexture.from BaseTexture.from}.
 * Otherwise, these `from` calls throw an exception. Using this property
 * can be useful if you want to enforce preloading all assets with
 * {@link PIXI.Loader Loader}.
 *
 * @static
 * @name STRICT_TEXTURE_CACHE
 * @memberof PIXI.settings
 * @type {boolean}
 * @default false