Package`CreatePackageCache[
 pkgContext,
 pkgDir,
 Package`AutloadPackage->boolean]

Package`DeclareLoad[
 {symbols},
 context,
 Package`HiddenImport->boolean,
 Path->pathspec,
 Package`ExportedContexts->{contexts}]

Package`ActivateLoad[
 symbol,
 {symbols},
 context,
 {Package`HiddenImport->boolean, Path->pathspec}
 ]

Package["TestPKG`"]

PackageScope["blumpf"]
PackageExport["Blah"]
PackageExport["Blah2"]

Package`ActivateLoad[loadMyTools,
 {loadMyTools},
 "MyTools`",
 {Package`HiddenImport -> True, Path -> Automatic}]

$InstallationDirectory/SystemFiles/Components/MXNetLink/*.m
$InstallationDirectory/SystemFiles/Components/NeuralNetworks/*.m
$InstallationDirectory/SystemFiles/Components/Iconize/*.m
$InstallationDirectory/SystemFiles/Components/Macros/*.m
$InstallationDirectory/AddOns/Applications/Parallel/Kernel/sysload.m
$InstallationDirectory/SystemFiles/Autoload/PacletManager/Kernel/Documentation.m
$InstallationDirectory/SystemFiles/Autoload/PacletManager/Kernel/Manager.m
$InstallationDirectory/SystemFiles/Kernel/SystemResources/MacOSX-x86-64/sysinit.m