code: public boolean removeParameter(String paramName) 
      throws IllegalArgumentException {
          log.trace("enter PostMethod.removeParameter(String)");
  
          if (paramName == null) {
              throw new IllegalArgumentException(
                  "Argument passed to removeParameter(String) cannot be null");
          }
          boolean removed = false;
          Iterator<NameValuePair> iter = this.params.iterator();
  
          while (iter.hasNext()) {
              NameValuePair pair = iter.next();
  
              if (paramName.equals(pair.getName())) {
                  iter.remove();
                  removed = true;
              }
          }
          return removed;
      }
docs: Removes all parameters with the given paramName. If there is more than
  one parameter with the given paramName, all of them are removed.  If
  there is just one, it is removed.  If there are none, then the request
  is ignored.
  
  @param paramName The parameter name to remove.
  
  @return true if at least one parameter was removed
  
  @throws IllegalArgumentException When the parameter name passed is null
  
  @since 2.0