public Operation removePragmaDirective(String directive){
  String existingDirectives=getRequestHeader(PRAGMA_HEADER);
  if (existingDirectives != null) {
    directive=existingDirectives.replace(directive,"");
    addRequestHeader(PRAGMA_HEADER,directive);
  }
  return this;
}

public Operation removePragmaDirective ( String directive ) { String existingDirectives = getRequestHeader ( PRAGMA_HEADER ) ; if ( existingDirectives != null ) { directive = existingDirectives . replace ( directive , "" ) ; addRequestHeader ( PRAGMA_HEADER , directive ) ; } return this ; }
removes a directive . lower case strings must be used
