How to attach a file on .sagews (Cloud Sage Math)

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I know I can load a file, like load('file.sage'), but this command only allows me to load a file once. On the other hand attach command keeps the file updating. But if I put on a .sagews (Sage WorkSheet) attach('file.sage') brings me an error or warning thing.

ERROR:

 This is a spoilerError in lines 1-1 Traceback (most recent call last):   File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 905, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals   File "", line 1, in <module>   File "sage/misc/lazy_import.pyx", line 379, in sage.misc.lazy_import.LazyImport.__call__ (/projects/sage/sage-6.10/src/build/cythonized/sage/misc/lazy_import.c:3560)
    return self._get_object()(*args, **kwds)   File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/repl/attach.py", line 338, in attach
    load(filename, globals(), attach=True)   File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/repl/load.py", line 285, in load
    exec(code, globals)   File "/projects/79bea2f2-8dbb-40b0-9160-311c880b827f/.sage/temp/compute2-us/24690/resolve.sageWkbRWj.py", line 5, in <module>
    _sage_const_2 = Integer(2); _sage_const_1 = Integer(1); _sage_const_0 = Integer(0); _sage_const_1en6 = RealNumber('1e-6'); _sage_const_5 = Integer(5); _sage_const_2p5 = RealNumber('2.5'); _sage_const_4 = Integer(4); _sage_const_100 = Integer(100); _sage_const_4p5en16 = RealNumber('4.5e-16'); _sage_const_1p5
= RealNumber('1.5'); _sage_const_1p6 = RealNumber('1.6'); _sage_const_p5 = RealNumber('.5'); _sage_const_1en12 = RealNumber('1e-12'); _sage_const_1en14
= RealNumber('1e-14') NameError: name 'Integer' is not defined