ZERO_ADDRESS = '0x{:040x}'.format(0)
ZERO_CONTENT = '0x{:064x}'.format(0)
MINIMUM_FEE_UNITS = 21000
MINIMUM_FEE_PRICE = 1000000000
DEFAULT_FEE_LIMIT = 8000000
MAX_UINT = int('0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 16)