'Read a double word, it returns None if ad is not an address.
The parameter section is the section where ad is. It\'s just use for
optimization and used to not recall get_section.'

def read_dword(self, ad, section=None):

    if (section is None):
        section = self.__binary.get_section(ad)
        if (section is None):
            return None
    return section.read_dword(ad)
