Add additional Staging initializer

src/main/java/com/imsweb/staging/Staging.java

@@ -4,6 +4,7 @@
 package com.imsweb.staging;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Calendar;
@@ -58,14 +59,23 @@ private Staging(StagingDataProvider provider) {
     }
 
     /**
-     * Create an instance of the Staging object with a pre-constructed provider
+     * Create an instance of the Staging object based on a provider
      * @param provider StagingDataProvider
      * @return a Staging instance
      */
     public static Staging getInstance(StagingDataProvider provider) {
         return new Staging(provider);
     }
 
+    /**
+     * Create an instance of the Staging object based on an InputStream
+     * @param is InputStream pointing to algoruthm zip file
+     * @return a Staging instance
+     */
+    public static Staging getInstance(InputStream is) throws IOException {
+        return new Staging(new ExternalStagingFileDataProvider(is));
+    }
+
     /**
      * Create an instance of the Staging object based on a Path representing an algorithm zip file
      * @param algorithmPath path to an algorithm zip file

src/test/java/com/imsweb/staging/ExternalStagingFileDataProviderTest.java

@@ -18,7 +18,7 @@ class ExternalStagingFileDataProviderTest extends FileDataProviderTest {
     @BeforeAll
     static void setup() throws IOException {
         try (InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("external_algorithm.zip")) {
-            _STAGING = Staging.getInstance(new ExternalStagingFileDataProvider(is));
+            _STAGING = Staging.getInstance(is);
         }
     }