Encodes a map as JSON. This should probably be a Map<String, dynamic>, but
this is not a constraint that is checked.
Consider using niceJson() instead.
Encodes data as nicely formatted human-readable JSON.
indent is the indent character added to the start of each line. By default,
this is a single space, but other good options are two spaces or a tab ('\t').
maxContentLength is the maximum length of a single entry.
maxLineLength is the maximum length of a single line, including key and indent.
Any keys in alwaysExpandKeys will have their values expanded, regardless
of line length.