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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def generate(env):
 """Add Builders and construction variables for lex to an Environment."""

    c_file, cxx_file = SCons.Tool.createCFileBuilders(env)

    # C
    c_file.add_action(".l", LexAction)
    c_file.add_emitter(".l", lexEmitter)

    c_file.add_action(".lex", LexAction)
    c_file.add_emitter(".lex", lexEmitter)

    # Objective-C
    cxx_file.add_action(".lm", LexAction)
    cxx_file.add_emitter(".lm", lexEmitter)

    # C++
    cxx_file.add_action(".ll", LexAction)
    cxx_file.add_emitter(".ll", lexEmitter)

    env["LEX"]      = env.Detect("flex") or "lex"
    env["LEXFLAGS"] = SCons.Util.CLVar("")
    env["LEXCOM"] = "$LEX $LEXFLAGS -t $SOURCES > $TARGET"