Add toModifiableCopy to request and response

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpRequest.java

@@ -27,12 +27,19 @@ public interface HttpRequest extends HttpMessage {
     SmithyUri uri();
 
     /**
-     * Get a modifiable version of the request.
+     * Get a modifiable version of the request, or returns the current request if it's already modifiable.
      *
-     * @return the modifiable request.
+     * @return the modifiable request or current request.
      */
     ModifiableHttpRequest toModifiable();
 
+    /**
+     * Creates a modifiable copy of the request, even if the current request is modifiable.
+     *
+     * @return the modifiable copy of this request.
+     */
+    ModifiableHttpRequest toModifiableCopy();
+
     /**
      * Creates an unmodifiable copy of the request, or returns it as is if it is already unmodifiable.
      *

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpRequestImpl.java

@@ -31,6 +31,11 @@ public HttpRequest toUnmodifiable() {
 
     @Override
     public ModifiableHttpRequest toModifiable() {
+        return toModifiableCopy();
+    }
+
+    @Override
+    public ModifiableHttpRequest toModifiableCopy() {
         var mod = new ModifiableHttpRequestImpl();
         mod.setHttpVersion(httpVersion);
         mod.setMethod(method);
@@ -113,7 +118,7 @@ public HttpRequest build() {
         @Override
         public ModifiableHttpRequest buildModifiable() {
             beforeBuild();
-            return modifiableHttpRequest.copy();
+            return modifiableHttpRequest.toModifiableCopy();
         }
     }
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpResponse.java

@@ -23,6 +23,13 @@ public interface HttpResponse extends HttpMessage {
      */
     ModifiableHttpResponse toModifiable();
 
+    /**
+     * Creates a modifiable copy of the response, even if the current response is modifiable.
+     *
+     * @return the modifiable copy of this response.
+     */
+    ModifiableHttpResponse toModifiableCopy();
+
     /**
      * Creates an unmodifiable copy of the request, or returns it as is if it is already unmodifiable.
      *

http/http-api/src/main/java/software/amazon/smithy/java/http/api/HttpResponseImpl.java

@@ -26,6 +26,11 @@ public HttpResponse toUnmodifiable() {
 
     @Override
     public ModifiableHttpResponse toModifiable() {
+        return toModifiableCopy();
+    }
+
+    @Override
+    public ModifiableHttpResponse toModifiableCopy() {
         var mod = new ModifiableHttpResponseImpl();
         mod.setHttpVersion(httpVersion);
         mod.setStatusCode(statusCode);
@@ -94,7 +99,7 @@ public HttpResponse build() {
 
         @Override
         public ModifiableHttpResponse buildModifiable() {
-            return modifiableResponse.copy();
+            return modifiableResponse.toModifiableCopy();
         }
     }
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/ModifiableHttpRequest.java

@@ -39,11 +39,4 @@ default void setUri(URI uri) {
     default ModifiableHttpRequest toModifiable() {
         return this;
     }
-
-    /**
-     * Create a copy of the modifiable request.
-     *
-     * @return the standalone copy.
-     */
-    ModifiableHttpRequest copy();
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/ModifiableHttpRequestImpl.java

@@ -88,7 +88,7 @@ public HttpRequest toUnmodifiable() {
     }
 
     @Override
-    public ModifiableHttpRequest copy() {
+    public ModifiableHttpRequest toModifiableCopy() {
         return new ModifiableHttpRequestImpl(this);
     }
 

http/http-api/src/main/java/software/amazon/smithy/java/http/api/ModifiableHttpResponse.java

@@ -20,11 +20,4 @@ public interface ModifiableHttpResponse extends ModifiableHttpMessage, HttpRespo
     default ModifiableHttpResponse toModifiable() {
         return this;
     }
-
-    /**
-     * Create a copy of the modifiable response.
-     *
-     * @return the standalone copy.
-     */
-    ModifiableHttpResponse copy();
 }

http/http-api/src/main/java/software/amazon/smithy/java/http/api/ModifiableHttpResponseImpl.java

@@ -86,7 +86,7 @@ public HttpResponse toUnmodifiable() {
     }
 
     @Override
-    public ModifiableHttpResponse copy() {
+    public ModifiableHttpResponse toModifiableCopy() {
         return new ModifiableHttpResponseImpl(this);
     }
 

http/http-api/src/test/java/software/amazon/smithy/java/http/api/SmithyHttpRequestImplTest.java

@@ -161,7 +161,7 @@ public void modifiableCopyIsIndependent() throws Exception {
                 .withAddedHeader("foo", "bar")
                 .buildModifiable();
 
-        var copy = modifiable.copy();
+        var copy = modifiable.toModifiableCopy();
         copy.headers().addHeader("foo", "baz");
 
         assertThat(modifiable.headers().allValues("foo"), contains("bar"));

http/http-api/src/test/java/software/amazon/smithy/java/http/api/SmithyHttpResponseImplTest.java

@@ -150,7 +150,7 @@ public void modifiableCopyIsIndependent() {
                 .withAddedHeader("foo", "bar")
                 .buildModifiable();
 
-        var copy = modifiable.copy();
+        var copy = modifiable.toModifiableCopy();
         copy.headers().addHeader("foo", "baz");
 
         assertThat(modifiable.headers().allValues("foo"), contains("bar"));