Provide a way to get the underlying pubgrub range from a Range.

Author: Kaholaz

src/version.rs

@@ -262,12 +262,19 @@ impl From<pubgrub::Range<Version>> for Range {
         Self { spec, range }
     }
 }
+
 impl From<Version> for Range {
     fn from(version: Version) -> Self {
         pubgrub::Range::singleton(version).into()
     }
 }
 
+impl From<Range> for pubgrub::Range<Version> {
+    fn from(range: Range) -> Self {
+        range.range
+    }
+}
+
 impl fmt::Debug for Range {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_tuple("Range").field(&self.spec).finish()