function set( ticks ) {
	/* eslint-disable no-invalid-this */
	if ( !isNull( ticks ) && !isNonNegativeInteger( ticks ) ) {
		throw new TypeError( format( 'invalid assignment. `%s` must be a nonnegative integer or null. Value: `%s`.', 'yNumTicks', ticks ) );
	}
	if ( ticks !== this._yNumTicks ) {
		debug( 'Current value: %d.', this._yNumTicks );

		this._yNumTicks = ticks;
		debug( 'New value: %d.', this._yNumTicks );

		this.emit( 'change' );
	}
}
Sets the number of y-axis tick marks.

@private
@param {(NonNegativeInteger|null)} ticks - number of ticks
@throws {TypeError} must be a nonnegative integer or null