[source, ruby]
----
response = client.indices.create(
  index: 'keep_types_example',
  body: {
    settings: {
      analysis: {
        analyzer: {
          my_analyzer: {
            tokenizer: 'standard',
            filter: [
              'extract_alpha'
            ]
          }
        },
        filter: {
          extract_alpha: {
            type: 'keep_types',
            types: [
              '<ALPHANUM>'
            ]
          }
        }
      }
    }
  }
)
puts response
----
