Adding upstream version 6.0.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tests/test_docs.py

@@ -0,0 +1,30 @@
+import doctest
+import inspect
+import unittest
+
+import sqlglot
+import sqlglot.optimizer
+import sqlglot.transforms
+
+
+def load_tests(loader, tests, ignore):
+    """
+    This finds and runs all the doctests
+    """
+
+    modules = {
+        mod
+        for module in [sqlglot, sqlglot.transforms, sqlglot.optimizer]
+        for _, mod in inspect.getmembers(module, inspect.ismodule)
+    }
+
+    assert len(modules) >= 20
+
+    for module in modules:
+        tests.addTests(doctest.DocTestSuite(module))
+
+    return tests
+
+
+if __name__ == "__main__":
+    unittest.main()