```ruby
module Swagger::Data
  class Mime
    @@types = [
      'text/plain',
      'text/plain; charset=utf-8',
      'application/json',
      'application/hal+json',
      'application/problem+json',
      'application/postscript',
      'application/pdf',
      'application/postscript',
      'application/octet-stream',
      'application/xml',
      'application/zip',
      'text/xml',
      'text/tab-separated-values',
      'application/vnd.api+json',
      'application/vnd.github+json',
      'application/vnd.github.v3+json',
      'application/vnd.github.v3.raw+json',
      'application/vnd.github.v3.text+json',
      'application/vnd.github.v3.html+json',
      'application/vnd.github.v3.full+json',
      'application/vnd.github.v3.diff',
      'application/vnd.github.v3.patch'
    ]

    def self.valid?(type)
      @@types.include?(type)
    end
  end
end
```

Add text/json as data MIME type
user
```ruby
module Swagger::Data
  class Mime
    @@types = [
      'text/plain',
      'text/json',
      'text/plain; charset=utf-8',
      'application/json',
      'application/hal+json',
      'application/problem+json',
      'application/postscript',
      'application/pdf',
      'application/postscript',
      'application/octet-stream',
      'application/xml',
      'application/zip',
      'text/xml',
      'text/tab-separated-values',
      'application/vnd.api+json',
      'application/vnd.github+json',
      'application/vnd.github.v3+json',
      'application/vnd.github.v3.raw+json',
      'application/vnd.github.v3.text+json',
      'application/vnd.github.v3.html+json',
      'application/vnd.github.v3.full+json',
      'application/vnd.github.v3.diff',
      'application/vnd.github.v3.patch'
    ]

    def self.valid?(type)
      @@types.include?(type)
    end
  end
end
```
assistant