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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 _get_from_java_home(self):
 """ Retrieves the Java library path according to the JAVA_HOME environment variable :return: The path to the JVM library, or None """

        # Get the environment variable
        java_home = os.getenv("JAVA_HOME")
        if java_home and os.path.exists(java_home):
            # Get the real installation path
            java_home = os.path.realpath(java_home)

            # Cygwin has a bug in realpath
            if not os.path.exists(java_home):
                java_home = os.getenv("JAVA_HOME")

            # Look for the library file
            return self.find_libjvm(java_home)