private URL genesisConfigSource(final File genesisFile) {
    try {
      return genesisFile.toURI().toURL();
    } catch (final IOException e) {
      throw new ParameterException(
          this.commandLine, String.format("Unable to load genesis URL %s.", genesisFile), e);
    }
  }
Builds Vertx instance from VertxOptions. Visible for testing.

@param vertxOptions Instance of VertxOptions
@return Instance of Vertx.
app/src/main/java/org/hyperledger/besu/cli/BesuCommand.java