Should return true if this instance is able to parse the fragment value into a Selector implementation.
If this method returns true, parseFragment() will be called by the SelectorFactory with the fragment value.
The fragment specification URL, see "conformsTo" in https://www.w3.org/TR/annotation-model/#fragment-selector
Parses the fragment into a Selector implementation.
This method must only be called if canParseFragment() returns true for the specified fragment value.
Note that the parsing can fail and return null even if canParseFragment() returns true.
Parser for media fragment selectors.
https://www.w3.org/TR/media-frags/