JetFile: PackageSimpleNameLeadingDot.kt
  PACKAGE_DIRECTIVE
    PsiElement(package)('package')
    PsiWhiteSpace(' ')
    PsiErrorElement:Package name must be a '.'-separated identifier list
      PsiElement(DOT)('.')
    REFERENCE_EXPRESSION
      PsiElement(IDENTIFIER)('a')
  IMPORT_LIST
    <empty list>