Construct the response to listing the tree in gitea.

src/gitea_client/error.rs

@@ -0,0 +1,25 @@
+use std::error::Error;
+
+#[derive(Debug, Clone)]
+pub(crate) enum GiteaClientError {
+    Static(#[allow(dead_code)] &'static str),
+    String(#[allow(dead_code)] String),
+    NoTotalCountHeaderInResponse,
+}
+
+impl std::fmt::Display for GiteaClientError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            GiteaClientError::Static(s) => write!(f, "GiteaClientError: {}", s),
+            GiteaClientError::String(s) => write!(f, "GiteaClientError: {}", s),
+            GiteaClientError::NoTotalCountHeaderInResponse => {
+                write!(
+                    f,
+                    "GiteaClientError: No x-total-count header returned in gitea response.",
+                )
+            }
+        }
+    }
+}
+
+impl Error for GiteaClientError {}