introduce UraClientConfiguration class to encapsulate client config

Legacy constructors use new pattern internally.

src/test/java/de/stklcode/pubtrans/ura/UraClientConfigurationTest.java

@@ -0,0 +1,34 @@
+package de.stklcode.pubtrans.ura;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit test for {@link UraClientConfiguration}.
+ *
+ * @author Stefan Kalscheuer
+ */
+public class UraClientConfigurationTest {
+    @Test
+    public void configBuilderTest() {
+        final String baseURL = "https://ura.example.com";
+        final String instantPath = "/path/to/instant";
+        final String streamPath = "/path/to/stream";
+
+        // With Base-URL only.
+        UraClientConfiguration config = UraClientConfiguration.forBaseURL(baseURL).build();
+        assertEquals(baseURL, config.getBaseURL(), "Unexpected base URL");
+        assertEquals("/interfaces/ura/instant_V1", config.getInstantPath(), "Unexpected default instant path");
+        assertEquals("/interfaces/ura/stream_V1", config.getStreeamPath(), "Unexpected default stream path");
+
+        // With custom paths.
+        config = UraClientConfiguration.forBaseURL(baseURL)
+                .withInstantPath(instantPath)
+                .withStreamPath(streamPath)
+                .build();
+        assertEquals(baseURL, config.getBaseURL(), "Unexpected base URL");
+        assertEquals(instantPath, config.getInstantPath(), "Unexpected custom instant path");
+        assertEquals(streamPath, config.getStreeamPath(), "Unexpected custom stream path");
+    }
+}