Design a data structure for representing a NFA M, and write functions to read and write NFAs. (For all projects, the names of functions and the way that they are called are just suggestions; if you prefer a different style, that's fine.) read_nfa(file) - file: File containing definition of NFA M - Returns: The NFA M write_nfa (M, file ) - M : The NFA to write - file: File to write to - Effect: Writes definition of M to file NFA file format The NFA definition should have the following format. It should begin with a four-line header: 1. A whitespace-separated list of states, Q. 2. A whitespace-separated list of input symbols, . It should be disjoint from Q. Each symbol should be exactly one character long. 3. The start state, sQ. 4. A whitespace-separated list of accept states, FQ. The rest of the lines list the transitions, one transition per line. Each line has three fields, separated by whitespace: 1. The state qQ that the transition leaves from. 2. The symbol a that the transition reads, or \& for the empty string. 3. The state rQ that the transition goes to. For example, the following NFA ( N1 in the book): would be specified by the file (examples/sipser-n1.nfa)