<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def fixed_length_vector_encoded_sequences(self, vector_encoding_name):
 """ Encode alleles. 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() in amino_acid. Returns ------- numpy.array with shape (num sequences, sequence length, m) where m is vector_encoding_length(vector_encoding_name) """

        cache_key = (
            "fixed_length_vector_encoding",
            vector_encoding_name)
        if cache_key not in self.encoding_cache:
            index_encoded_matrix = amino_acid.index_encoding(
                self.fixed_length_sequences.values,
                amino_acid.AMINO_ACID_INDEX)
            vector_encoded = amino_acid.fixed_vectors_encoding(
                index_encoded_matrix,
                amino_acid.ENCODING_DATA_FRAMES[vector_encoding_name])
            result = vector_encoded[self.indices]
            self.encoding_cache[cache_key] = result
        return self.encoding_cache[cache_key]