anchor.diff:  
   Each <<mapping-params,mapping parameter>> specifies whether or not its setting
   can be updated on an existing field.
  -
  
positive.code: {}
  
  PUT twitter/_mapping/_doc <2>
  {
    "properties": {
      "name": {
        "type": "text"
      }
    }
  }
  
  PUT twitter/_mapping/_doc <3>
  {
    "properties": {
      "email": {
  
negative.code: --------------------------------------------------
  // CONSOLE
  <1> <<indices-create-index,Creates an index>> called `twitter` without any type mapping.
  <2> Uses the PUT mapping API to add a new field called `email` to the `_doc` mapping type.
  
  More information on how to define type mappings can be found in the
  <<mapping,mapping>> section.
  