code: public PropertySourcePropertyResolver addPropertySource(String name, @Nullable Map<String, ? super Object> values) {
          if (CollectionUtils.isNotEmpty(values)) {
              return addPropertySource(PropertySource.of(name, values));
          }
          return this;
      }
docs: Add a property source for the given map.
  
  @param name   The name of the property source
  @param values The values
  @return This environment