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var assert = require('mdast-util-assert')
assert({type: 'root', children: []})
assert({type: 'break'})
assert({type: 'listItem', checked: true, children: []})
// All OK.
assert({children: []})
// AssertionError: node should have a type: `{ children: [] }`
assert({type: 'paragraph', value: 'foo'})
// AssertionError: parent should have children: `{ type: 'paragraph', value: 'foo' }`