public Long getEstimateGas(final DataFetchingEnvironment environment) {
    final Optional<CallResult> result = executeCall(environment);
    return result.map(CallResult::getGasUsed).orElse(0L);
  }
Estimates the gas used for a call execution.

@param environment the DataFetchingEnvironment
@return the estimated gas used for the call execution
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/graphql/internal/pojoadapter/BlockAdapterBase.java