json_schema: {
      "$schema": "http://json-schema.org/draft-07/schema#",
      "$id": "https://readium.org/webpub-manifest/schema/extensions/epub/properties.schema.json",
      "title": "EPUB Extension - Link Properties",
      "type": "object",
      "properties": {
          "contains": {
              "description": "Identifies content contained in the linked resource, that cannot be strictly identified using a media type.",
              "type": "array",
              "items": {
                  "type": "string",
                  "enum": [
                      "mathml",
                      "onix",
                      "remote-resources",
                      "js",
                      "svg",
                      "xmp"
                  ]
              },
              "_uniqueItems": true
          },
          "layout": {
              "description": "Hints how the layout of the resource should be presented",
              "type": "string",
              "enum": [
                  "fixed",
                  "reflowable"
              ]
          },
          "media-overlay": {
              "description": "Location of a media-overlay for the resource referenced in the Link Object",
              "type": "string",
              "format": "uri-reference"
          },
          "overflow": {
              "description": "Suggested method for handling overflow while displaying the linked resource",
              "type": "string",
              "enum": [
                  "auto",
                  "paginated",
                  "scrolled",
                  "scrolled-continuous"
              ]
          },
          "spread": {
              "description": "Indicates the condition to be met for the linked resource to be rendered within a synthetic spread",
              "type": "string",
              "enum": [
                  "auto",
                  "both",
                  "none",
                  "landscape"
              ]
          },
          "encrypted": {
              "description": "Indicates that a resource is encrypted/obfuscated and provides relevant information for decryption",
              "type": "object",
              "properties": {
                  "algorithm": {
                      "description": "Identifies the algorithm used to encrypt the resource",
                      "type": "string",
                      "format": "uri"
                  },
                  "compression": {
                      "description": "Compression method used on the resource",
                      "type": "string"
                  },
                  "original-length": {
                      "description": "Original length of the resource in bytes before compression and/or encryption",
                      "type": "integer"
                  },
                  "profile": {
                      "description": "Identifies the encryption profile used to encrypt the resource",
                      "type": "string",
                      "format": "uri"
                  },
                  "scheme": {
                      "description": "Identifies the encryption scheme used to encrypt the resource",
                      "type": "string",
                      "format": "uri"
                  }
              },
              "required": [
                  "algorithm"
              ]
          }
      }
  }