add get bytes func

gojo/builtins/_bytes.mojo

@@ -212,3 +212,11 @@ struct Bytes(Stringable, Sized, CollectionElement):
     fn capacity(self) -> Int:
         """Returns the capacity of the Bytes struct."""
         return self._vector.capacity
+
+    fn copy(self) -> Self:
+        """Returns a copy of the Bytes struct. Only copies up to what has been written to the Bytes struct."""
+        # Copy elements up to the write position, don't need to copy over empty elements from end of the vector.
+        var bytes_copy = Self(size=self.write_position)
+        for i in range(self.write_position):
+            bytes_copy.append(self._vector[i])
+        return bytes_copy

gojo/strings/builder.mojo

@@ -46,6 +46,26 @@ struct StringBuilder(Stringable, Sized, io.Writer, io.ByteWriter, io.StringWrite
         """
         # Don't need to add a null terminator because we can pass the length of the string.
         return str(self._vector)
+
+    fn get_bytes(self) -> DynamicVector[Int8]:
+        """
+        Returns a copy of the byte array of the string builder.
+
+        Returns:
+          The byte array of the string builder.
+        """
+        return self._vector.copy()._vector
+
+    fn get_null_terminated_bytes(self) -> DynamicVector[Int8]:
+        """
+        Returns a copy of the byte array of the string builder with a null terminator.
+
+        Returns:
+          The byte array of the string builder with a null terminator.
+        """
+        var new_bytes = self._vector.copy()._vector
+        new_bytes.append(0)
+        return new_bytes
 
     fn write(inout self, src: Bytes) -> Result[Int]:
         """