```js

registerLayout('centering', class {

async intrinsicSizes() {}

async layout(children, edges, constraints, styleMap) {

// (1) Determine our (inner) available size.

const availableInlineSize = constraints.fixedInlineSize - edges.inline;

static inputProperties = ['--a-number'];

static childInputProperties = ['--a-string'];

async intrinsicSizes() {}

async layout(children, edges, constraints, styleMap) {

// We can read our own style:

styleMap.get('--a-number').value === 42;

registerLayout('basic-inline', class {

static layoutOptions = {childDisplay: 'normal'};

async intrinsicSizes() {}

async layout(children, edges, constraints, styleMap) {

// Determine our (inner) available size.

const availableInlineSize = constraints.fixedInlineSize - edges.inline;

const availableBlockSize = constraints.fixedBlockSize !== null ?

constraints.fixedBlockSize - edges.block : null;

const constraints = {

const childConstraints = {

availableInlineSize,

availableBlockSize,

};

// Layout the next line, the produced line will try and respect the

// availableInlineSize given, you could use this to achieve a column

// effect or similar.

const fragment = await child.layoutNextFragment(constraints, childBreakToken);

const fragment = await child.layoutNextFragment(childConstraints, childBreakToken);

childFragments.push(fragment);

// Position the fragment, note we could do something special here, like

// placing all the lines on a "rythmic grid", or similar.

||||||| parent of a2dd8db ([css-layout-api][explainer] add mandatory intrinsicSizes function)

// Position the fragment, note we coulld do something special here, like

// placing all the lines on a "rythimic grid", or similar.

fragment.inlineOffset = edges.inlineStart;

fragment.blockOffset = blockOffset;

```js

registerLayout('special-multi-col', class {

async intrinsicSizes() {}

async layout(children, edges, constraints, styleMap, breakToken) {

for (let child of children) {

// Create a constraint space with a fragmentation line.

```js

registerLayout('basic-inline', class {

async intrinsicSizes() {}

async layout(children, edges, constraints, styleMap, breakToken) {

// We can check if we need to fragment in the block direction.