<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def setup_main_filler(name: str, environment: Dict[Any, Any]=None) -> Dict[str, Dict[str, Any]]: """ Kick off the filler generation process by creating the general filler scaffold with a test name and general information about the testing environment. For tests for the main chain, the `environment` parameter is expected to be a dictionary with some or all of the following keys: | key | description | +========================+=================================+ | ``"currentCoinbase"`` | the coinbase address | | ``"currentNumber"`` | the block number | | ``"previousHash"`` | the hash of the parent block | | ``"currentDifficulty"``| the block's difficulty | | ``"currentGasLimit"`` | the block's gas limit | | ``"currentTimestamp"`` | the timestamp of the block | """

    return setup_filler(name, merge(DEFAULT_MAIN_ENVIRONMENT, environment or {}))