A Resolver is an accessor capable of interpreting an xpath for a given kind of
object.
XPath are mainly used for xml documents but can also be used for more general
objets like nodes and beans.
author  Johann Sorel

There might be multiple resolvers who can support the same object.
The priority ensure the most accurate one will be used.
return  priority. high priority resolver should be tested first

Test if this resolver can work with given class.
param  clazz
return  true if clazz is supported

Test if this resolver can work with given object.
param  candidate
return  true if object is supported

Resolve given xpath for object.
param  path xpath
param  candidate object to evaluate
return  resolved value