@Nonnull
	private String appendExpressionImports(@Nonnull StringBuilder code, @Nonnull String expression) {
		// Add imports from the user defined expression.
		// Remove the imports from the expression once copied to the output code.
		StringBuilder expressionBuffer = new StringBuilder();
		expression.lines().forEach(l -> {
			Matcher matcher = IMPORT_EXTRACT_PATTERN.matcher(l);
			if (matcher.find()) {
				code.append(matcher.group(1)).append('\n');
			} else {
				expressionBuffer.append(l).append('\n');
			}
		});
		return expressionBuffer.toString();
	}
Expressions can contain imports at the top so that the end-user can work without needing fully qualified names.
We want to take those out and append them to the class we're generating, and update the expression to remove
the imports so that we can slap it into the method body later without syntax issues coming from imports being
used in a method body.

@param code
		Class code to append imports to.
@param expression
		Expression to extract imports from.

@return Modified expression <i>(without imports)</i>
recaf-core/src/main/java/software/coley/recaf/services/compile/stub/ExpressionHostingClassStubGenerator.java