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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 variable_length_to_fixed_length_vector_encoding( self, vector_encoding_name, left_edge=4, right_edge=4, max_length=15):
 """ Encode variable-length sequences using a fixed-length encoding designed for preserving the anchor positions of class I peptides. The sequences must be of length at least left_edge + right_edge, and at most max_length. Parameters vector_encoding_name : string How to represent amino acids. One of "BLOSUM62", "one-hot", etc. Full list of supported vector encodings is given by available_vector_encodings(). left_edge : int, size of fixed-position left side right_edge : int, size of the fixed-position right side max_length : sequence length of the resulting encoding Returns ------- numpy.array with shape (num sequences, max_length, m) where m is vector_encoding_length(vector_encoding_name) """

        cache_key = (
            "fixed_length_vector_encoding",
            vector_encoding_name,
            left_edge,
            right_edge,
            max_length)
        if cache_key not in self.encoding_cache:
            fixed_length_sequences = (
                self.sequences_to_fixed_length_index_encoded_array(
                    self.sequences,
                    left_edge=left_edge,
                    right_edge=right_edge,
                    max_length=max_length))
            result = amino_acid.fixed_vectors_encoding(
                fixed_length_sequences,
                amino_acid.ENCODING_DATA_FRAMES[vector_encoding_name])
            assert result.shape[0] == len(self.sequences)
            self.encoding_cache[cache_key] = result
        return self.encoding_cache[cache_key]