code: def _fuse_one_block(
      block, ops_arrangement, var_constraints, transform_pattern
  ):
      fusion_status = False
      for op in list(block.operations):
          for b in op.blocks:
              block_changed = True
              while block_changed:
                  block_changed = _fuse_one_block(
                      b,
                      ops_arrangement,
                      var_constraints,
                      transform_pattern,
                  )
  
          ops_arrangement_root_var = list(
              ops_arrangement.functions.values()
          )[0].function_inputs[0]
          fusion_status, pattern = _detect_pattern(
              op, ops_arrangement_root_var, block
          )
  
          if fusion_status:
              fusion_status &= var_constraints(pattern)
  
          if fusion_status:
              transform_pattern(pattern)
              return fusion_status
  
      return fusion_status
  
imports: import itertools
  import warnings
  from functools import partial
  from coremltools.converters.mil.mil.passes.helper import block_context_manager
  from ...mil.passes import pass_registry
label_desc: Use image node_id 4 for calling a global function with example usage: _fuse_one_block(block, ops_arrangement, var_constraints, transform_pattern) and returns: fusion_status, fusion_status