f.SystemName,
		f.Filename,
	}
}

type functionKey struct {
	startLine                  int64
	name, systemName, fileName string
}

// combineHeaders checks that all profiles can be merged and returns
// their combined profile.
func combineHeaders(srcs []*Profile) (*Profile, error) {
	for _, s := range srcs[1:] {
		if err := srcs[0].compatible(s); err != nil {
			return nil, err
		}
	}

		f.SystemName,
		f.Filename,
	}
}

type functionKey struct {
	startLine                  int64
	name, systemName, fileName string
}

// combineHeaders checks that all profiles can be merged and returns
// their combined profile.
func combineHeaders(srcs []*Profile) (*Profile, error) {
	for _, s := range srcs[1:] {
		if err := srcs[0].compatible(s); err != nil {
			return nil, err
		}
	}