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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def extensions():
 """Returns list of `cython` extensions for `lazy_cythonize`."""

    import numpy
    from Cython.Build import cythonize
    ext = [
            Extension('phydmslib.numutils', ['phydmslib/numutils.pyx'],
                    include_dirs=[numpy.get_include()],
                    extra_compile_args=['-Wno-unused-function']),
          ]      
    return cythonize(ext)