anchor.diff:  	if(!length(cached_materials))
   		return null
   
  -	. = list()
  +	var/materials_of_category
   	for(var/m in cached_materials)
   		if(cached_materials[m] < mat_amount)
   			continue
  
positive.code: 			continue
  		if(no_flags && (category_flags & no_flags))
  			continue
  		.[material] = cached_materials[m]
  
  /**
   * Gets the most common material in the object.
  
negative.code: 	if(!length(cached_materials))
  		return null
  
  	var/materials_of_type
  	for(var/m in cached_materials)
  		if(cached_materials[m] < mat_amount)
  			continue
  		var/datum/material/material = GET_MATERIAL_REF(m)
  		if(exact ? material.type != m : !istype(material, mat_type))
  			continue
  		LAZYSET(materials_of_type, material, cached_materials[m])
  
  	return materials_of_type
  
  /**
   * Fetches a list of all of the materials this object has with the desired material category.
  