Source: blah.js

/** Class representing a point. */
class Point {
    /**
     * Create a point.
     * @param {number} x - The x value.
     * @param {number} y - The y value.
     */
    constructor(x, y) {
        // ...
    }

    /**
     * Get the x value.
     * @return {number} The x value.
     */
    getX() {
        // ...
    }

    /**
     * Get the y value.
     * @return {number} The y value.
     */
    getY() {
        // ...
    }
}

/**
 * Class representing a dot.
 * @extends Point
 */
class Dot extends Point {
    /**
     * Create a dot.
     * @param {number} x - The x value.
     * @param {number} y - The y value.
     * @param {number} width - The width of the dot, in pixels.
     */
    constructor(x, y, width) {
        // ...
    }

    /**
     * Get the dot's width.
     * @return {number} The dot's width, in pixels.
     */
    getWidth() {
        // ...
    }
}