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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 get_config_h_filename():
 """Return the path of pyconfig.h."""

    if _PYTHON_BUILD:
        if os.name == "nt":
            inc_dir = os.path.join(_PROJECT_BASE, "PC")
        else:
            inc_dir = _PROJECT_BASE
    else:
        inc_dir = get_path('platinclude')
    return os.path.join(inc_dir, 'pyconfig.h')