Focusing on a function will remove any sample that does not include that function. In addition, it re-roots the call tree so that the function is the only root of the tree. This can combine multiple function call sites across a profile into one call node.
聚焦于函数，将移除所有不包含该函数的样本。此外，还会重新将调用树的根指定为该函数。如此可将分析记录中的多个函数调用点合并为单个调用节点。