liquibase-core/src/main/java/liquibase/parser/core/yaml/YamlChangeLogParser.java
private Boolean getGlobalParam(Map property) {
		Boolean global = null;
		Object globalObj = property.get("global");
		if (globalObj == null) {
			// default behaviour before liquibase 3.4
			global = true;
		} else {
			global = (Boolean) globalObj;
		}
		return global;
	}
private Boolean getGlobalParam(Map property) {
		Boolean global = null;
		Object globalObj = property.get("global");
		if (globalObj == null) {
			// default behaviour before liquibase 3.4
			global = true;
		} else {
			global = (Boolean) globalObj;
		}
		return global;
	}
Extract the global parameter from the properties.

@param property the map of props
@return the global param