{
  "validator": [ "Simplest", { "required_fields": [ "friend" ] } ],
  "renderer": "TestRenderer",
  "header": [
    { "Subject": "Hello [% friend.name() %]"     },
    { "From":    "Test Sender <test@test.com>" },
    { "X-Test":  "This is an unrendered [% friend %] test.", ":renderer": null  }
  ],
  "alternatives": [
    {
      "type": "text/plain",
      "body": "We don't support tests."
    },
    {
      "attributes": {
        "content_type": "text/html",
        "charset": "utf-8"
      },
      "header": [ { "X-Cantata": "[% friend %] canta y no llores" } ],
      "body": "<p>This is the unrendered [% friend %] HTML part.  Renderer: null</p>",
      "renderer": null
    },
    {
      "container_type": "multipart/related",
      "type": "text/html",
      "path": "better-alternative.html",
      "attributes": { "charset": "utf-8" },
      "attachments": [
        {
          "type": "image/jpeg",
          "path": "logo.jpg"
        }
      ]
    }
  ],
  "attachments": [
    {
      "type": "application/pdf",
      "path": "bogus-report.pdf",
      "attributes": { "filename": "report.pdf" }
    }
  ]
}