contract pDNADistributedRegistry is Ownable {
  mapping(string => address) private registry;

  event Profiled(string eGrid, address indexed property);
  event Unprofiled(string eGrid, address indexed property);

  /**
   * this function's abi should never change and always maintain backwards compatibility
   */
  function getProperty(string memory _eGrid) public view returns (address property) {
    property = registry[_eGrid];
  }

  function profileProperty(string memory _eGrid, address _property) public onlyOwner {
    require(bytes(_eGrid).length > 0, "eGrid must be non-empty string");
    require(_property != address(0), "property address must be non-null");
    require(registry[_eGrid] == address(0), "property must not already exist in land registry");

    registry[_eGrid] = _property;
    emit Profiled(_eGrid, _property);
  }

  function unprofileProperty(string memory _eGrid) public onlyOwner {
    address property = getProperty(_eGrid);
    require(property != address(0), "property must exist in land registry");

    registry[_eGrid] = address(0);
    emit Unprofiled(_eGrid, property);
  }
}
function getProperty(string memory _eGrid) public view returns (address property) {
  property = registry[_eGrid];
}

/**
 * this function's abi should never change and always maintain backwards compatibility
 */