<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Using Python, parse a given XML document and output the names of all elements with the “class” attribute.
<|im_end|>
<|im_start|>assistant
from xml.etree import ElementTree

def find_elements(tree):
    elements = []
    for elem in tree.iter():
        if 'class' in elem.attrib:
            elements.append(elem.tag)
    return elements<|im_end|>
