Tests if the specified string contains a local file pathname or a file URL on the local machine.
Examples:
isLocalFile (
"/home/users/joe/schema/myschema.xsd"
) == true
isLocalFile (
"file:/C:/schema/myschema.xsd"
) == true
isLocalFile (
"http://www.w3.org/2001/XMLSchema.xsd"
) == false