Add must_use annotations where appropriate

ldp/src/rdf_source.rs

@@ -117,6 +117,7 @@ impl SerializationOptions {
     /// Filter triples that match the predicate.
     ///
     /// A return value of `true` means that it the triple ought to be included in the serialization.
+    #[must_use]
     pub fn with_filter<F>(self, filter: F) -> Self
     where
         F: Fn(TripleRef<'_>) -> bool + 'static,

ldp/src/resource.rs

@@ -46,6 +46,7 @@ impl ResourceRequestBuilder {
     }
 
     /// Creates a new request with the given HTTP client.
+    #[must_use]
     pub fn with_client_and_url(client: ClientWithMiddleware, url: Url) -> Self {
         Self {
             client,
@@ -56,6 +57,7 @@ impl ResourceRequestBuilder {
     }
 
     /// If the HTTP response includes a [describedby](https://www.w3.org/TR/ldp/#link-relation-describedby) link rel, then it will be followed.
+    #[must_use]
     pub fn follow_described_by(mut self, value: bool) -> Self {
         self.follow_described_by = value;
         self
@@ -65,12 +67,14 @@ impl ResourceRequestBuilder {
     ///
     /// Repeated calls are additive. By default, all formats — even non-RDF formats — are accepted.
     /// If your intention is to process non-RDF data, then this should not be called.
+    #[must_use]
     pub fn accept_rdf_format(mut self, format: RdfFormat) -> Self {
         self.formats.push(format);
         self
     }
 
     /// Restrict the request to all the formats supported by the underlying parser.
+    #[must_use]
     pub fn accept_all_rdf_formats(mut self) -> Self {
         self.formats = vec![
             RdfFormat::N3,