if (oldValue != null) {
String oldText = trimTrailing(header.getText().substring(oldValue.getStartOffsetInParent(), header.getTextLength()));
if (!oldText.isEmpty()) oldText += ",\n ";
headerValue = oldText + headerValue;
}
header.replace(createHeader(manifestFile.getProject(), headerName, headerValue));
}
else {
addHeader(manifestFile, createHeader(manifestFile.getProject(), headerName, headerValue));
}
}