Semantics.HeadersValuesSourceA map keyed by header names.
type t = {location : Syntax.location;from : Syntax.abstract_location;abstractLoc : Syntax.abstract_location;ethSrc : Frenetic_kernel.Packet.dlAddr;ethDst : Frenetic_kernel.Packet.dlAddr;vlan : Frenetic_kernel.Packet.int16;vlanPcp : Frenetic_kernel.Packet.dlVlanPcp;vswitch : int64;vport : int64;ethType : Frenetic_kernel.Packet.dlTyp;ipProto : Frenetic_kernel.Packet.nwProto;ipSrc : Frenetic_kernel.Packet.nwAddr;ipDst : Frenetic_kernel.Packet.nwAddr;tcpSrcPort : Frenetic_kernel.Packet.tpPort;tcpDstPort : Frenetic_kernel.Packet.tpPort;}