JsonUtf8Encoder([String indent, dynamic toEncodable(object), int bufferSize = DEFAULT_BUFFER_SIZE ])

Create converter.

If indent is non-null, the converter attempts to "pretty-print" the JSON, and uses indent as the indentation. Otherwise the result has no whitespace outside of string literals. If indent contains characters that are not valid JSON whitespace characters, the result will not be valid JSON. JSON whitespace characters are space (U+0020), tab (U+0009), line feed (U+000a) and carriage return (U+000d) (ECMA 404).

The bufferSize is the size of the internal buffers used to collect UTF-8 code units. If using startChunkedConversion, it will be the size of the chunks.

The JSON encoder handles numbers, strings, booleans, null, lists and maps directly.

Any other object is attempted converted by toEncodable to an object that is of one of the convertible types.

If toEncodable is omitted, it defaults to calling .toJson() on the object.

Source 

JsonUtf8Encoder([String indent,
                 toEncodable(object),
                 int bufferSize = DEFAULT_BUFFER_SIZE])
    : _indent = _utf8Encode(indent),
      _toEncodable = toEncodable,
      _bufferSize = bufferSize;