KtFile: LINQ.kt
  PACKAGE_DIRECTIVE
    <empty list>
  IMPORT_LIST
    <empty list>
  FUN
    PsiElement(fun)('fun')
    PsiWhiteSpace(' ')
    PsiElement(IDENTIFIER)('foo')
    VALUE_PARAMETER_LIST
      PsiElement(LPAR)('(')
      PsiElement(RPAR)(')')
    PsiWhiteSpace(' ')
    BLOCK
      PsiElement(LBRACE)('{')
      PsiWhiteSpace('\n    ')
      BINARY_EXPRESSION
        BINARY_EXPRESSION
          BINARY_EXPRESSION
            REFERENCE_EXPRESSION
              PsiElement(IDENTIFIER)('l')
            PsiWhiteSpace(' ')
            OPERATION_REFERENCE
              PsiElement(IDENTIFIER)('filter')
            PsiWhiteSpace(' ')
            LAMBDA_EXPRESSION
              FUNCTION_LITERAL
                PsiElement(LBRACE)('{')
                BLOCK
                  DOT_QUALIFIED_EXPRESSION
                    REFERENCE_EXPRESSION
                      PsiElement(IDENTIFIER)('it')
                    PsiElement(DOT)('.')
                    REFERENCE_EXPRESSION
                      PsiElement(IDENTIFIER)('x')
                PsiElement(RBRACE)('}')
          PsiWhiteSpace(' ')
          OPERATION_REFERENCE
            PsiElement(IDENTIFIER)('map')
          PsiWhiteSpace(' ')
          LAMBDA_EXPRESSION
            FUNCTION_LITERAL
              PsiElement(LBRACE)('{')
              BLOCK
                DOT_QUALIFIED_EXPRESSION
                  REFERENCE_EXPRESSION
                    PsiElement(IDENTIFIER)('it')
                  PsiElement(DOT)('.')
                  REFERENCE_EXPRESSION
                    PsiElement(IDENTIFIER)('foo')
              PsiElement(RBRACE)('}')
        PsiWhiteSpace(' ')
        OPERATION_REFERENCE
          PsiElement(IDENTIFIER)('aggregate')
        PsiWhiteSpace(' ')
        LAMBDA_EXPRESSION
          FUNCTION_LITERAL
            PsiElement(LBRACE)('{')
            VALUE_PARAMETER_LIST
              VALUE_PARAMETER
                PsiElement(IDENTIFIER)('a')
              PsiElement(COMMA)(',')
              PsiWhiteSpace(' ')
              VALUE_PARAMETER
                PsiElement(IDENTIFIER)('b')
            PsiWhiteSpace(' ')
            PsiElement(ARROW)('->')
            PsiWhiteSpace(' ')
            BLOCK
              BINARY_EXPRESSION
                REFERENCE_EXPRESSION
                  PsiElement(IDENTIFIER)('a')
                PsiWhiteSpace(' ')
                OPERATION_REFERENCE
                  PsiElement(PLUS)('+')
                PsiWhiteSpace(' ')
                REFERENCE_EXPRESSION
                  PsiElement(IDENTIFIER)('b')
            PsiElement(RBRACE)('}')
      PsiWhiteSpace('\n')
      PsiElement(RBRACE)('}')