TreeItem.this - multiple declarations

Function TreeItem.this

this(
  string id
);

Function TreeItem.this

this(
  string id,
  dstring label,
  string iconRes = null
);

Function TreeItem.this

this(
  string id,
  UIString label,
  string iconRes = null
);

Function TreeItem.this

this(
  string id,
  string labelRes,
  string iconRes = null
);