code: public String getProp(String key) {
      if (this.specProperties.containsKey(key)) {
        return this.specProperties.getProperty(key);
      }
      return this.commonProperties.getProperty(key);
    }
docs: Get the value of a property.
  
  @param key property key
  @return value associated with the key as a string or <code>null</code> if the property is not set