code: def to_bstr(x):
      sign, man, exp, bc = x
      return (
          ["", "-"][sign]
          + numeral(man, size=bitcount(man), base=2)
          + ("e%i" % exp)
      )
  
imports: import math
  from bisect import bisect
  import sys
  from .backend import MPZ, MPZ_TYPE, MPZ_ZERO, MPZ_ONE, MPZ_TWO, MPZ_FIVE, BACKEND, STRICT, HASH_MODULUS, HASH_BITS, gmpy, sage, sage_utils
  from .libintmath import giant_steps, trailtable, bctable, lshift, rshift, bitcount, trailing, sqrt_fixed, numeral, isqrt, isqrt_fast, sqrtrem, bin_to_radix
label_desc: Use image node_id 58 for calling a global function with example usage: to_bstr(x) and returns: unknown