PathMapper instances provide methods for mapping paths from their JCR
string representation to their Oak representation and vice versa.
The Oak representation of a path consists of a forward slash followed by the
names of the respective items in the Tree
separated by forward slashes.
Returns the JCR path for the given Oak path. The given path is
expected to have come from a valid Oak repository that contains
only valid paths whose name elements only use proper namespace
mappings. If that's not the case, either a programming error or
a repository corruption has occurred and an appropriate unchecked
exception gets thrown.