query block using <blockhash> as key.

def getblock(self, blockhash: str) -> dict:
        '''query block using <blockhash> as key.'''

        query = 'block.raw.dws?coin={net}&hash={blockhash}'.format(
            net=self.format_name(self.net),
            blockhash=blockhash,
        )
        return cast(dict, self.get_url(self.explorer_url + query))