public double getDouble(final String name) {
    if (containsKey(name)) {
      return Double.parseDouble(get(name).trim());
    } else {
      throw new UndefinedPropertyException("Missing required property '" + name
          + "'");
    }
  }
Returns the double representation of the value. If the value is null, then a
UndefinedPropertyException will be thrown. If the value isn't a double, then a parse exception
will be thrown.
dss-appconn/appconns/dss-eventchecker-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/eventchecker/utils/Props.java