code: public UrlStringBuilder setParameters(String namespace, Map<String, List<String>> parameters) {
          for (final String name : parameters.keySet()) {
              Validate.notNull(name, "parameter map cannot contain any null keys");
          }
  
          this.parameters.clear();
          this.addParameters(namespace, parameters);
          return this;
      }
docs: Removes all existing parameters and sets the contents of the specified Map as the parameters.
  
  @param namespace String to prepend to each parameter name in the Map
  @param parameters Map of parameters to set
  @return this