fails:System::String#[] returns a System::String
fails:System::String#[] with index, length returns the substring starting at the given index with the given length
fails:System::String#[] with Range returns the substring given by the offsets of the range
fails:System::String#[] with Range returns an empty string if range.begin is inside self and > real end
fails:System::String#[] with Range always taints resulting strings when self is tainted
fails:System::String#[] with Regexp always taints resulting strings when self or regexp is tainted
fails:System::String#[] with Regexp, index always taints resulting strings when self or regexp is tainted
fails:System::String#[] with Regexp, index returns a System::String
fails:System::String#[] with String returns other_str if it occurs in self
fails:System::String#[] with String taints resulting strings when other is tainted
fails:System::String#[] with String doesn't set $~
fails:System::String#[] with String returns nil if there is no match
fails:System::String#[] with String returns a subclass instance when given a subclass instance
fails:System::String#[] with String returns a System::String
fails:System::String#[] with System::String taints resulting strings when other is tainted
fails:System::String#[] with System::String returns a subclass instance when given a subclass instance
