feat: ability to extract delay value from the response

Closes: #14

Author: nergal-perm

src/main/java/ewc/utilities/testableio/responses/DelayedResponse.java

@@ -43,4 +43,13 @@ public <R> R next(BiFunction<Object, Map<String, Object>, R> transformer) {
         Thread.sleep(this.millis);
         return this.response.next(transformer);
     }
+
+    @Override
+    public Object peekContent() {
+        return this.response.peekContent();
+    }
+
+    public int delayMillis() {
+        return this.millis;
+    }
 }

src/main/java/ewc/utilities/testableio/responses/ExceptionResponse.java

@@ -27,7 +27,7 @@
 import java.util.Map;
 import java.util.function.BiFunction;
 
-public class ExceptionResponse implements Response{
+public class ExceptionResponse implements Response {
     private final RuntimeException exception;
 
     public ExceptionResponse(RuntimeException exception) {
@@ -38,4 +38,9 @@ public ExceptionResponse(RuntimeException exception) {
     public <R> R next(BiFunction<Object, Map<String, Object>, R> transformer) {
         throw this.exception;
     }
+
+    @Override
+    public Object peekContent() {
+        return "%s: %s".formatted(this.exception.getClass().getSimpleName(), this.exception.getMessage());
+    }
 }

src/main/java/ewc/utilities/testableio/responses/RawResponse.java

@@ -73,4 +73,9 @@ public <R> R convertedUsing(BiFunction<Object, Map<String, Object>, R> converter
     public <R> R next(BiFunction<Object, Map<String, Object>, R> transformer) {
         return this.convertedUsing(transformer);
     }
+
+    @Override
+    public Object peekContent() {
+        return this.content;
+    }
 }

src/main/java/ewc/utilities/testableio/responses/Response.java

@@ -33,4 +33,7 @@ public interface Response {
     default Response peek() {
         return this;
     }
+
+    Object peekContent();
+
 }

src/main/java/ewc/utilities/testableio/responses/SequencedResponse.java

@@ -54,6 +54,11 @@ public Response peek() {
         return this.responses[this.index.currentValue()].peek();
     }
 
+    @Override
+    public Object peekContent() {
+        return this.peek().peekContent();
+    }
+
     private static final class IncrementalIndex {
         /**
          * The thread-safe counter providing the index of the next response to be returned.