+ /**
+ * Constructs the URL for the REST symbol endpoint
+ *
+ * @param id
+ * the accession id (Ensembl or external)
+ * @param species
+ * a species name recognisable by Ensembl
+ * @param type
+ * an optional type to filter the response (gene, transcript,
+ * translation)
+ * @return
+ */
+ protected URL getUrl(String id, Species species, String... type)