anchor.diff:  schema of the loaded DataFrame as shown in listing 7.2:
   
   .Printing the schema of our data
  -[source,scala]
  +[subs="specialcharacters,quotes"]
   ----
   events.printSchema()
   
  
positive.code: [source,json]
  ----
  {
    [yellow-background]#"action": "created"#,
    "issue": {
      "url": // ...
    }
  
negative.code: ----
  {
    "ref": "0.0.1",
    "ref_type": "tag",
    "master_branch": "master",
    // ...
  }
  