How to use the @pixi/utils.removeItems function in @pixi/utils

removeChildAt(index)
    {
        const child = this.getChildAt(index);

        // ensure child transform will be recalculated..
        child.parent = null;
        child.transform._parentID = -1;
        removeItems(this.children, index, 1);

        // ensure bounds will be recalculated
        this._boundsID++;

        // TODO - lets either do all callbacks or all events.. not both!
        this.onChildrenChange(index);
        child.emit('removed', this);
        this.emit('childRemoved', child, this, index);

        return child;
    }

removeChildAt(index)
    {
        const child = this.getChildAt(index);

        // ensure child transform will be recalculated..
        child.parent = null;
        child.transform._parentID = -1;
        removeItems(this.children, index, 1);

        // ensure bounds will be recalculated
        this._boundsID++;

        // TODO - lets either do all callbacks or all events.. not both!
        this.onChildrenChange(index);
        child.emit('removed', this);
        this.emit('childRemoved', child, this, index);

        return child;
    }

setChildIndex(child, index)
    {
        if (index < 0 || index >= this.children.length)
        {
            throw new Error(`The index ${index} supplied is out of bounds ${this.children.length}`);
        }

        const currentIndex = this.getChildIndex(child);

        removeItems(this.children, currentIndex, 1); // remove from old position
        this.children.splice(index, 0, child); // add at new position

        this.onChildrenChange(index);
    }

setChildIndex(child, index)
    {
        if (index < 0 || index >= this.children.length)
        {
            throw new Error(`The index ${index} supplied is out of bounds ${this.children.length}`);
        }

        const currentIndex = this.getChildIndex(child);

        removeItems(this.children, currentIndex, 1); // remove from old position
        this.children.splice(index, 0, child); // add at new position

        this.onChildrenChange(index);
    }

let div = this.div;

        div.style.left = `${rect.left}px`;
        div.style.top = `${rect.top}px`;
        div.style.width = `${this.renderer.width}px`;
        div.style.height = `${this.renderer.height}px`;

        for (let i = 0; i < this.children.length; i++)
        {
            const child = this.children[i];

            if (child.renderId !== this.renderId)
            {
                child._accessibleActive = false;

                removeItems(this.children, i, 1);
                this.div.removeChild(child._accessibleDiv);
                this.pool.push(child._accessibleDiv);
                child._accessibleDiv = null;

                i--;

                if (this.children.length === 0)
                {
                    this.deactivate();
                }
            }
            else
            {
                // map div to display..
                div = child._accessibleDiv;
                let hitArea = child.hitArea;

chars.push({
                texture: charData.texture,
                line,
                charCode,
                position: new Point(pos.x + charData.xOffset + (this._letterSpacing / 2), pos.y + charData.yOffset),
            });
            pos.x += charData.xAdvance + this._letterSpacing;
            lastLineWidth = pos.x;
            maxLineHeight = Math.max(maxLineHeight, (charData.yOffset + charData.texture.height));
            prevCharCode = charCode;

            if (lastBreakPos !== -1 && maxWidth > 0 && pos.x > maxWidth)
            {
                ++spacesRemoved;
                removeItems(chars, 1 + lastBreakPos - spacesRemoved, 1 + i - lastBreakPos);
                i = lastBreakPos;
                lastBreakPos = -1;

                lineWidths.push(lastBreakWidth);
                maxLineWidth = Math.max(maxLineWidth, lastBreakWidth);
                line++;

                pos.x = 0;
                pos.y += data.lineHeight;
                prevCharCode = null;
            }
        }

        const lastChar = text.charAt(text.length - 1);

        if (lastChar !== '\r' && lastChar !== '\n')

if (texture._glTextures[this.CONTEXT_UID])
        {
            this.unbind(texture);

            gl.deleteTexture(texture._glTextures[this.CONTEXT_UID].texture);
            texture.off('dispose', this.destroyTexture, this);

            delete texture._glTextures[this.CONTEXT_UID];

            if (!skipRemove)
            {
                const i = this.managedTextures.indexOf(texture);

                if (i !== -1)
                {
                    removeItems(this.managedTextures, i, 1);
                }
            }
        }
    }

chars.push({
                texture: charData.texture,
                line,
                charCode,
                position: new Point(pos.x + charData.xOffset + (this._letterSpacing / 2), pos.y + charData.yOffset),
            });
            pos.x += charData.xAdvance + this._letterSpacing;
            lastLineWidth = pos.x;
            maxLineHeight = Math.max(maxLineHeight, (charData.yOffset + charData.texture.height));
            prevCharCode = charCode;

            if (lastBreakPos !== -1 && maxWidth > 0 && pos.x > maxWidth)
            {
                ++spacesRemoved;
                removeItems(chars, 1 + lastBreakPos - spacesRemoved, 1 + i - lastBreakPos);
                i = lastBreakPos;
                lastBreakPos = -1;

                lineWidths.push(lastBreakWidth);
                maxLineWidth = Math.max(maxLineWidth, lastBreakWidth);
                line++;

                pos.x = 0;
                pos.y += data.lineHeight;
                prevCharCode = null;
            }
        }

        const lastChar = text.charAt(text.length - 1);

        if (lastChar !== '\r' && lastChar !== '\n')