match method
Implementation
SelectorBuilder match(String fieldName, String pattern,
{bool? multiLine, bool? caseInsensitive, bool? dotAll, bool? extended}) {
_addExpression(fieldName, {
'\$regex': BsonRegexp(pattern,
multiLine: multiLine,
caseInsensitive: caseInsensitive,
dotAll: dotAll,
extended: extended)
});
return this;
}