How to use the @contentful/rich-text-types.BLOCKS.HEADING_4 function in @contentful/rich-text-types

const markTypes = new Map([['emphasis', 'italic'], ['strong', 'bold'], ['inlineCode', 'code']]);
const markTypeFor = (node: MarkdownNode) => {
  return markTypes.get(node.type);
};

const isLink = (node: MarkdownNode): node is MarkdownLinkNode => {
  return node.type === 'link';
};

const nodeContainerTypes = new Map([
  ['delete', 'block'],
  [BLOCKS.HEADING_1, 'block'],
  [BLOCKS.HEADING_2, 'block'],
  [BLOCKS.HEADING_3, 'block'],
  [BLOCKS.HEADING_4, 'block'],
  [BLOCKS.HEADING_5, 'block'],
  [BLOCKS.HEADING_6, 'block'],
  [BLOCKS.LIST_ITEM, 'block'],
  [BLOCKS.UL_LIST, 'block'],
  [BLOCKS.OL_LIST, 'block'],
  [BLOCKS.QUOTE, 'block'],
  [BLOCKS.HR, 'block'],
  [BLOCKS.PARAGRAPH, 'block'],
  [INLINES.HYPERLINK, 'inline'],
  ['text', 'text'],
  ['emphasis', 'text'],
  ['strong', 'text'],
  ['inlineCode', 'text'],
]);

const isBlock = (nodeType: string) => {

Mark,
  Text,
  BLOCKS,
  MARKS,
  INLINES,
  Block,
  Inline,
  helpers,
} from '@contentful/rich-text-types';

const defaultNodeRenderers: RenderNode = {
  [BLOCKS.PARAGRAPH]: (node, next) =&gt; `<p>${next(node.content)}</p>`,
  [BLOCKS.HEADING_1]: (node, next) =&gt; `<h1>${next(node.content)}</h1>`,
  [BLOCKS.HEADING_2]: (node, next) =&gt; `<h2>${next(node.content)}</h2>`,
  [BLOCKS.HEADING_3]: (node, next) =&gt; `<h3>${next(node.content)}</h3>`,
  [BLOCKS.HEADING_4]: (node, next) =&gt; `<h4>${next(node.content)}</h4>`,
  [BLOCKS.HEADING_5]: (node, next) =&gt; `<h5>${next(node.content)}</h5>`,
  [BLOCKS.HEADING_6]: (node, next) =&gt; `<h6>${next(node.content)}</h6>`,
  [BLOCKS.EMBEDDED_ENTRY]: (node, next) =&gt; `<div>${next(node.content)}</div>`,
  [BLOCKS.UL_LIST]: (node, next) =&gt; `<ul>${next(node.content)}</ul>`,
  [BLOCKS.OL_LIST]: (node, next) =&gt; `<ol>${next(node.content)}</ol>`,
  [BLOCKS.LIST_ITEM]: (node, next) =&gt; `<li>${next(node.content)}</li>`,
  [BLOCKS.QUOTE]: (node, next) =&gt; `<blockquote>${next(node.content)}</blockquote>`,
  [BLOCKS.HR]: () =&gt; '<hr>',
  [INLINES.ASSET_HYPERLINK]: node =&gt; defaultInline(INLINES.ASSET_HYPERLINK, node as Inline),
  [INLINES.ENTRY_HYPERLINK]: node =&gt; defaultInline(INLINES.ENTRY_HYPERLINK, node as Inline),
  [INLINES.EMBEDDED_ENTRY]: node =&gt; defaultInline(INLINES.EMBEDDED_ENTRY, node as Inline),
  [INLINES.HYPERLINK]: (node, next) =&gt; `<a href="${node.data.uri}">${next(node.content)}</a>`,
};

const defaultMarkRenderers: RenderMark = {
  [MARKS.BOLD]: text =&gt; `<b>${text}</b>`,

import React, { ReactNode } from 'react';
import { Block, BLOCKS, Document, Inline, INLINES, MARKS, Text } from '@contentful/rich-text-types';
import { nodeToReactComponent } from './util/nodeListToReactComponents';

const defaultNodeRenderers: RenderNode = {
  [BLOCKS.DOCUMENT]: (node, children) => children,
  [BLOCKS.PARAGRAPH]: (node, children) =&gt; <p>{children}</p>,
  [BLOCKS.HEADING_1]: (node, children) =&gt; <h1>{children}</h1>,
  [BLOCKS.HEADING_2]: (node, children) =&gt; <h2>{children}</h2>,
  [BLOCKS.HEADING_3]: (node, children) =&gt; <h3>{children}</h3>,
  [BLOCKS.HEADING_4]: (node, children) =&gt; <h4>{children}</h4>,
  [BLOCKS.HEADING_5]: (node, children) =&gt; <h5>{children}</h5>,
  [BLOCKS.HEADING_6]: (node, children) =&gt; <h6>{children}</h6>,
  [BLOCKS.EMBEDDED_ENTRY]: (node, children) =&gt; <div>{children}</div>,
  [BLOCKS.UL_LIST]: (node, children) =&gt; <ul>{children}</ul>,
  [BLOCKS.OL_LIST]: (node, children) =&gt; <ol>{children}</ol>,
  [BLOCKS.LIST_ITEM]: (node, children) =&gt; <li>{children}</li>,
  [BLOCKS.QUOTE]: (node, children) =&gt; <blockquote>{children}</blockquote>,
  [BLOCKS.HR]: () =&gt; <hr>,
  [INLINES.ASSET_HYPERLINK]: node =&gt; defaultInline(INLINES.ASSET_HYPERLINK, node as Inline),
  [INLINES.ENTRY_HYPERLINK]: node =&gt; defaultInline(INLINES.ENTRY_HYPERLINK, node as Inline),
  [INLINES.EMBEDDED_ENTRY]: node =&gt; defaultInline(INLINES.EMBEDDED_ENTRY, node as Inline),
  [INLINES.HYPERLINK]: (node, children) =&gt; <a href="{node.data.uri}">{children}</a>,
};

const defaultMarkRenderers: RenderMark = {
  [MARKS.BOLD]: text =&gt; <b>{text}</b>,

export const defaultOptions = {
  overrides: {},
  createElement: React.createElement
};

const assetElementMap = {
  image: Image,
  video: Video,
  audio: Audio
};

const tagMap = {
  [BLOCKS.HEADING_1]: 'h1',
  [BLOCKS.HEADING_2]: 'h2',
  [BLOCKS.HEADING_3]: 'h3',
  [BLOCKS.HEADING_4]: 'h4',
  [BLOCKS.HEADING_5]: 'h5',
  [BLOCKS.HEADING_6]: 'h6',
  [BLOCKS.PARAGRAPH]: 'p',
  [BLOCKS.UL_LIST]: 'ul',
  [BLOCKS.OL_LIST]: 'ol',
  [BLOCKS.LIST_ITEM]: 'li',
  [BLOCKS.QUOTE]: 'blockquote',
  [BLOCKS.HR]: 'hr',
  [INLINES.HYPERLINK]: 'a',
  [MARKS.BOLD]: 'strong',
  [MARKS.ITALIC]: 'em',
  [MARKS.UNDERLINE]: 'u',
  [MARKS.CODE]: 'code'
};

const entryMap = {

}}>inline: {type} , sys.id: {node.data.target.sys.id}
}

const defaultMarkRenderers = {
  [MARKS.BOLD]: (text, key) =&gt; <strong>{text}</strong>,
  [MARKS.ITALIC]: (text, key) =&gt; <em>{text}</em>,
  [MARKS.UNDERLINE]: (text, key) =&gt; <u>{text}</u>,
  [MARKS.CODE]: (text, key) =&gt; <code>{text}</code>
}

const defaultNodeRenderers = {
  [BLOCKS.PARAGRAPH]: (node, key, next) =&gt; <p>{next(node.content, key, next)}</p>,
  [BLOCKS.HEADING_1]: (node, key, next) =&gt; <h1>{next(node.content, key, next)}</h1>,
  [BLOCKS.HEADING_2]: (node, key, next) =&gt; <h2>{next(node.content, key, next)}</h2>,
  [BLOCKS.HEADING_3]: (node, key, next) =&gt; <h3>{next(node.content, key, next)}</h3>,
  [BLOCKS.HEADING_4]: (node, key, next) =&gt; <h4>{next(node.content, key, next)}</h4>,
  [BLOCKS.HEADING_5]: (node, key, next) =&gt; <h5>{next(node.content, key, next)}</h5>,
  [BLOCKS.HEADING_6]: (node, key, next) =&gt; <h6>{next(node.content, key, next)}</h6>,
  [BLOCKS.EMBEDDED_ENTRY]: (node, key, next) =&gt; <div>{next(node.content, key, next)}</div>,
  [BLOCKS.UL_LIST]: (node, key, next) =&gt; <ul>{next(node.content, key, next)}</ul>,
  [BLOCKS.OL_LIST]: (node, key, next) =&gt; <ol>{next(node.content, key, next)}</ol>,
  [BLOCKS.LIST_ITEM]: (node, key, next) =&gt; <li>{next(node.content, key, next)}</li>,
  [BLOCKS.QUOTE]: (node, key, next) =&gt; <blockquote>{next(node.content, key, next)}</blockquote>,
  [BLOCKS.HR]: (node, key) =&gt; <hr>,
  [INLINES.ASSET_HYPERLINK]: (node, key) =&gt; defaultInline(INLINES.ASSET_HYPERLINK, node, key),
  [INLINES.ENTRY_HYPERLINK]: (node, key) =&gt; defaultInline(INLINES.ENTRY_HYPERLINK, node, key),
  [INLINES.EMBEDDED_ENTRY]: (node, key) =&gt; defaultInline(INLINES.EMBEDDED_ENTRY, node, key),
  [INLINES.HYPERLINK]: (node, key, next) =&gt; {
    return (<a href="{node.data.uri}">{next(node.content, key, next)}</a>)
  },
  text: ({ marks, value }, key, markRenderer) =&gt; {
    return marks.length ? (