private long getFromBlockNumber(final Optional<BlockParameter> startBlockParameter) {
    return startBlockParameter
        .map(this::resolveBlockNumber)
        .orElseGet(() -> Math.max(0, blockchainQueries.headBlockNumber() - DEFAULT_RANGE_BLOCK));
  }
Response.

@param requestContext the request context
@return the json rpc response
consensus/common/src/main/java/org/hyperledger/besu/consensus/common/jsonrpc/AbstractGetSignerMetricsMethod.java