Fixing test to not run on old version of Python. Style.

Author: ppisl

graalpython/com.oracle.graal.python.test/src/tests/test_string.py

@@ -897,7 +897,8 @@ def test_startswith(self):
         self.checkequal(False, 'helloworld', 'startswith', 'lowo', 3, 6)
         self.checkequal(True, '', 'startswith', '', 0, 1)
         self.checkequal(True, '', 'startswith', '', 0, 0)
-        self.checkequal(False, '', 'startswith', '', 1, 0)
+        if (sys.version_info.major >= 3 and sys.version_info.minor >= 6):
+            self.checkequal(False, '', 'startswith', '', 1, 0)
 
         # test negative indices
         self.checkequal(True, 'hello', 'startswith', 'he', 0, -1)

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/str/StringBuiltins.java

@@ -588,6 +588,7 @@ boolean startsWith(String self, PTuple prefix, Object start, Object end) {
         }
 
         @Fallback
+        @SuppressWarnings("unused")
         boolean general(Object self, Object prefix, Object start, Object end) {
             throw raise(TypeError, "startswith first arg must be str or a tuple of str, not %p", prefix);
         }