public static NatMethod fromString(final String str) {
    for (final NatMethod mode : NatMethod.values()) {
      if (mode.name().equalsIgnoreCase(str)) {
        return mode;
      }
    }
    return null;
  }
Map NatMethod from string value.

@param str the Nat Method in String format
@return instance of mapped NatMethod
nat/src/main/java/org/hyperledger/besu/nat/NatMethod.java