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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 _serialize_quadratic_biases(quadratic, edgelist):
 """Serializes the quadratic biases. Args: each edge is of the form (node1, node2). Returns: str: base 64 encoded string of little endian 8 byte floats, one for each of the edges in quadratic. Ordered by edgelist. Example: 'AAAAAAAA8L8AAAAAAADwP5qZmZmZmdk/' """

    # assumes quadratic is upper-triangular or reflected in edgelist
    quadratic_list = [quadratic[(u, v)] if (u, v) in quadratic else quadratic[(v, u)]
                      for u, v in edgelist]
    quadratic_bytes = struct.pack('<' + 'd' * len(quadratic), *quadratic_list)
    return base64.b64encode(quadratic_bytes).decode('utf-8')