[Core] The SummaryPrinter should only depend on api classes

A plugin interface like the SummaryPrinter should only depend on
classes in cucumber.api packages.

core/src/main/java/cucumber/api/SummaryPrinter.java

@@ -1,12 +1,14 @@
 package cucumber.api;
 
-import cucumber.runtime.Runtime;
-
 /**
  * Interface for plugins that print a summary after test execution.
  *
  * @see Plugin
  */
 public interface SummaryPrinter extends Plugin {
-    void print(Runtime runtime);
+    /**
+     * Handles the printing of the summary to the console
+     * @param summaryPrinter Provides method to print the stats, errors and snippets
+     */
+    void print(SummaryPrintingInterface summaryPrinting);
 }

core/src/main/java/cucumber/api/SummaryPrintingInterface.java

@@ -0,0 +1,31 @@
+package cucumber.api;
+
+import java.io.PrintStream;
+import java.util.List;
+
+/**
+ * Provides methods for printing the statistics, errors and snippets to
+ * a SummaryPrinter plugin.
+ *
+ */
+public interface SummaryPrintingInterface {
+    /**
+     * Prints the statistics to the PrintStream argument.
+     * @param out The PrintStrema to print to.
+     */
+    void printStats(PrintStream out);
+
+    /**
+     * Returns the errors that occurred during the execution of the test cases
+     * from the feature files.
+     * @return the errors.
+     */
+    List<Throwable> getErrors();
+
+    /**
+     * Returns the snippets created for the undefined steps encountered during
+     * the execution of the test cases from the feature files.
+     * @return the snippets.
+     */
+    List<String> getSnippets();
+}

core/src/main/java/cucumber/runtime/DefaultSummaryPrinter.java

@@ -1,6 +1,7 @@
 package cucumber.runtime;
 
 import cucumber.api.SummaryPrinter;
+import cucumber.api.SummaryPrintingInterface;
 
 import java.io.PrintStream;
 import java.util.List;
@@ -13,27 +14,27 @@ public DefaultSummaryPrinter() {
     }
 
     @Override
-    public void print(Runtime runtime) {
+    public void print(SummaryPrintingInterface summaryPrinting) {
         out.println();
-        printStats(runtime);
+        printStats(summaryPrinting);
         out.println();
-        printErrors(runtime);
-        printSnippets(runtime);
+        printErrors(summaryPrinting);
+        printSnippets(summaryPrinting);
     }
 
-    private void printStats(Runtime runtime) {
-        runtime.printStats(out);
+    private void printStats(SummaryPrintingInterface summaryPrinting) {
+        summaryPrinting.printStats(out);
     }
 
-    private void printErrors(Runtime runtime) {
-        for (Throwable error : runtime.getErrors()) {
+    private void printErrors(SummaryPrintingInterface summaryPrinting) {
+        for (Throwable error : summaryPrinting.getErrors()) {
             error.printStackTrace(out);
             out.println();
         }
     }
 
-    private void printSnippets(Runtime runtime) {
-        List<String> snippets = runtime.getSnippets();
+    private void printSnippets(SummaryPrintingInterface summaryPrinting) {
+        List<String> snippets = summaryPrinting.getSnippets();
         if (!snippets.isEmpty()) {
             out.append("\n");
             out.println("You can implement missing steps with the snippets below:");

core/src/main/java/cucumber/runtime/NullSummaryPrinter.java

@@ -1,11 +1,12 @@
 package cucumber.runtime;
 
 import cucumber.api.SummaryPrinter;
+import cucumber.api.SummaryPrintingInterface;
 
 public class NullSummaryPrinter implements SummaryPrinter {
 
     @Override
-    public void print(Runtime runtime) {
+    public void print(SummaryPrintingInterface summaryPrinting) {
         // Do nothing
     }
 

core/src/main/java/cucumber/runtime/Runtime.java

@@ -2,6 +2,7 @@
 
 import cucumber.api.StepDefinitionReporter;
 import cucumber.api.SummaryPrinter;
+import cucumber.api.SummaryPrintingInterface;
 import cucumber.api.event.TestRunFinished;
 import cucumber.runner.EventBus;
 import cucumber.runner.Runner;
@@ -24,7 +25,7 @@
 /**
  * This is the main entry point for running Cucumber features.
  */
-public class Runtime {
+public class Runtime implements SummaryPrintingInterface {
 
     final Stats stats; // package private to be available for tests.
     private final UndefinedStepsTracker undefinedStepsTracker = new UndefinedStepsTracker();
@@ -143,7 +144,7 @@ public void printSummary() {
         summaryPrinter.print(this);
     }
 
-    void printStats(PrintStream out) {
+    public void printStats(PrintStream out) {
         stats.printStats(out, runtimeOptions.isStrict());
     }